diff --git a/keyboards/handwired/bstk100/bstk100.c b/keyboards/handwired/bstk100/bstk100.c
new file mode 100644
index 0000000000..004b97004b
--- /dev/null
+++ b/keyboards/handwired/bstk100/bstk100.c
@@ -0,0 +1,18 @@
+/* Copyright 2021 FREE WING,Y.Sakamoto
+ * http://www.neko.ne.jp/~freewing/
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see .
+ */
+
+#include "bstk100.h"
diff --git a/keyboards/handwired/bstk100/bstk100.h b/keyboards/handwired/bstk100/bstk100.h
new file mode 100644
index 0000000000..42a6da437f
--- /dev/null
+++ b/keyboards/handwired/bstk100/bstk100.h
@@ -0,0 +1,43 @@
+/* Copyright 2021 FREE WING,Y.Sakamoto
+ * http://www.neko.ne.jp/~freewing/
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see .
+ */
+
+#pragma once
+
+#include "quantum.h"
+
+/* This is a shortcut to help you visually see your layout.
+ *
+ * The first section contains all of the arguments representing the physical
+ * layout of the board and position of the keys.
+ *
+ * The second converts the arguments into a two-dimensional array which
+ * represents the switch matrix.
+ */
+#define LAYOUT( \
+ k00, \
+ k34, k03, k02, k13, \
+ k10, k11, k12, k01, \
+ k20, k21, k22, k23, \
+ k30, k31, k32, k33, \
+ k40, k41, k43 \
+) { \
+ { k00, k01, k02, k03, KC_NO }, \
+ { k10, k11, k12, k13, KC_NO }, \
+ { k20, k21, k22, k23, KC_NO }, \
+ { k30, k31, k32, k33, k34 }, \
+ { k40, k41, KC_NO, k43, KC_NO } \
+}
diff --git a/keyboards/handwired/bstk100/config.h b/keyboards/handwired/bstk100/config.h
new file mode 100644
index 0000000000..6769f9b5c0
--- /dev/null
+++ b/keyboards/handwired/bstk100/config.h
@@ -0,0 +1,156 @@
+/*
+Copyright 2021 FREE WING,Y.Sakamoto
+http://www.neko.ne.jp/~freewing/
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program. If not, see .
+*/
+
+#pragma once
+
+#include "config_common.h"
+
+/* USB Device descriptor parameter */
+#define VENDOR_ID 0xFEED
+#define PRODUCT_ID 0xB100
+#define DEVICE_VER 0x0001
+#define MANUFACTURER FREE WING
+#define PRODUCT bstk100
+
+/* key matrix size */
+#define MATRIX_ROWS 5
+#define MATRIX_COLS 5
+
+/*
+ * Keyboard Matrix Assignments
+ *
+ * Change this to how you wired your keyboard
+ * COLS: AVR pins used for columns, left to right
+ * ROWS: AVR pins used for rows, top to bottom
+ * DIODE_DIRECTION: COL2ROW = COL = Anode (+), ROW = Cathode (-, marked on diode)
+ * ROW2COL = ROW = Anode (+), COL = Cathode (-, marked on diode)
+ *
+ */
+#define MATRIX_ROW_PINS { B6, B2, B3, B1, F7 }
+#define MATRIX_COL_PINS { B5, B4, E6, D7, C6 }
+#define UNUSED_PINS
+
+/* COL2ROW, ROW2COL */
+#define DIODE_DIRECTION COL2ROW
+
+/*
+ * Split Keyboard specific options, make sure you have 'SPLIT_KEYBOARD = yes' in your rules.mk, and define SOFT_SERIAL_PIN.
+ */
+#define SOFT_SERIAL_PIN D0 // or D1, D2, D3, E6
+
+// The state of the indicator pins when the LED is "on" - 1 for high
+#define LED_PIN_ON_STATE 0
+
+#define LED_NUM_LOCK_PIN D4
+#define LED_CAPS_LOCK_PIN D5
+#define LED_SCROLL_LOCK_PIN B0
+//#define LED_COMPOSE_PIN B3
+//#define LED_KANA_PIN B4
+
+//#define BACKLIGHT_PIN B7
+//#define BACKLIGHT_LEVELS 3
+//#define BACKLIGHT_BREATHING
+
+//#define RGB_DI_PIN E2
+//#ifdef RGB_DI_PIN
+//# define RGBLED_NUM 16
+//# define RGBLIGHT_HUE_STEP 8
+//# define RGBLIGHT_SAT_STEP 8
+//# define RGBLIGHT_VAL_STEP 8
+//# define RGBLIGHT_LIMIT_VAL 255 /* The maximum brightness level */
+//# define RGBLIGHT_SLEEP /* If defined, the RGB lighting will be switched off when the host goes to sleep */
+/*== all animations enable ==*/
+//# define RGBLIGHT_ANIMATIONS
+/*== or choose animations ==*/
+//# define RGBLIGHT_EFFECT_BREATHING
+//# define RGBLIGHT_EFFECT_RAINBOW_MOOD
+//# define RGBLIGHT_EFFECT_RAINBOW_SWIRL
+//# define RGBLIGHT_EFFECT_SNAKE
+//# define RGBLIGHT_EFFECT_KNIGHT
+//# define RGBLIGHT_EFFECT_CHRISTMAS
+//# define RGBLIGHT_EFFECT_STATIC_GRADIENT
+//# define RGBLIGHT_EFFECT_RGB_TEST
+//# define RGBLIGHT_EFFECT_ALTERNATING
+/*== customize breathing effect ==*/
+/*==== (DEFAULT) use fixed table instead of exp() and sin() ====*/
+//# define RGBLIGHT_BREATHE_TABLE_SIZE 256 // 256(default) or 128 or 64
+/*==== use exp() and sin() ====*/
+//# define RGBLIGHT_EFFECT_BREATHE_CENTER 1.85 // 1 to 2.7
+//# define RGBLIGHT_EFFECT_BREATHE_MAX 255 // 0 to 255
+//#endif
+
+/* Debounce reduces chatter (unintended double-presses) - set 0 if debouncing is not needed */
+#define DEBOUNCE 5
+
+/* define if matrix has ghost (lacks anti-ghosting diodes) */
+//#define MATRIX_HAS_GHOST
+
+/* Mechanical locking support. Use KC_LCAP, KC_LNUM or KC_LSCR instead in keymap */
+#define LOCKING_SUPPORT_ENABLE
+/* Locking resynchronize hack */
+#define LOCKING_RESYNC_ENABLE
+
+/* If defined, GRAVE_ESC will always act as ESC when CTRL is held.
+ * This is useful for the Windows task manager shortcut (ctrl+shift+esc).
+ */
+//#define GRAVE_ESC_CTRL_OVERRIDE
+
+/*
+ * Force NKRO
+ *
+ * Force NKRO (nKey Rollover) to be enabled by default, regardless of the saved
+ * state in the bootmagic EEPROM settings. (Note that NKRO must be enabled in the
+ * makefile for this to work.)
+ *
+ * If forced on, NKRO can be disabled via magic key (default = LShift+RShift+N)
+ * until the next keyboard reset.
+ *
+ * NKRO may prevent your keystrokes from being detected in the BIOS, but it is
+ * fully operational during normal computer usage.
+ *
+ * For a less heavy-handed approach, enable NKRO via magic key (LShift+RShift+N)
+ * or via bootmagic (hold SPACE+N while plugging in the keyboard). Once set by
+ * bootmagic, NKRO mode will always be enabled until it is toggled again during a
+ * power-up.
+ *
+ */
+//#define FORCE_NKRO
+
+/*
+ * Feature disable options
+ * These options are also useful to firmware size reduction.
+ */
+
+/* disable debug print */
+//#define NO_DEBUG
+
+/* disable print */
+//#define NO_PRINT
+
+/* disable action features */
+//#define NO_ACTION_LAYER
+//#define NO_ACTION_TAPPING
+//#define NO_ACTION_ONESHOT
+
+/* disable these deprecated features by default */
+#define NO_ACTION_MACRO
+#define NO_ACTION_FUNCTION
+
+/* Bootmagic Lite key configuration */
+//#define BOOTMAGIC_LITE_ROW 0
+//#define BOOTMAGIC_LITE_COLUMN 0
diff --git a/keyboards/handwired/bstk100/info.json b/keyboards/handwired/bstk100/info.json
new file mode 100644
index 0000000000..aec01fccc9
--- /dev/null
+++ b/keyboards/handwired/bstk100/info.json
@@ -0,0 +1,36 @@
+{
+ "keyboard_name": "bstk100",
+ "url": "http://www.neko.ne.jp/~freewing/",
+ "maintainer": "FREE WING",
+ "layouts": {
+ "LAYOUT": {
+ "layout": [
+ {"label": "k00", "x": 0, "y": 0},
+
+ {"label": "k34", "x": 0, "y": 1},
+ {"label": "k03", "x": 1, "y": 1},
+ {"label": "k02", "x": 2, "y": 1},
+ {"label": "k13", "x": 3, "y": 1},
+
+ {"label": "k10", "x": 0, "y": 2},
+ {"label": "k11", "x": 1, "y": 2},
+ {"label": "k12", "x": 2, "y": 2},
+ {"label": "k01", "x": 3, "y": 2},
+
+ {"label": "k20", "x": 0, "y": 3},
+ {"label": "k21", "x": 1, "y": 3},
+ {"label": "k22", "x": 2, "y": 3},
+ {"label": "k23", "x": 3, "y": 3},
+
+ {"label": "k30", "x": 0, "y": 4},
+ {"label": "k31", "x": 1, "y": 4},
+ {"label": "k32", "x": 2, "y": 4},
+ {"label": "k33", "x": 3, "y": 4, "h": 2},
+
+ {"label": "k40", "x": 0, "y": 5},
+ {"label": "k41", "x": 1, "y": 5},
+ {"label": "k43", "x": 2, "y": 5}
+ ]
+ }
+ }
+}
diff --git a/keyboards/handwired/bstk100/keymaps/default/keymap.c b/keyboards/handwired/bstk100/keymaps/default/keymap.c
new file mode 100644
index 0000000000..474921eeab
--- /dev/null
+++ b/keyboards/handwired/bstk100/keymaps/default/keymap.c
@@ -0,0 +1,53 @@
+/* Copyright 2021 FREE WING,Y.Sakamoto
+ * http://www.neko.ne.jp/~freewing/
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see .
+ */
+#include QMK_KEYBOARD_H
+
+// Defines names for use in layer keycodes and the keymap
+enum layer_names {
+ _BASE
+};
+
+// Defines the keycodes used by our macros in process_record_user
+enum custom_keycodes {
+ QMK00 = SAFE_RANGE
+};
+
+const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
+ /* Base */
+ [_BASE] = LAYOUT(
+ KC_NLCK,
+ KC_TAB, KC_PSLS, KC_PAST, KC_BSPC,
+ KC_P7, KC_P8, KC_P9, KC_PMNS,
+ KC_P4, KC_P5, KC_P6, KC_PPLS,
+ KC_P1, KC_P2, KC_P3, KC_PENT,
+ KC_P0, QMK00, KC_PDOT
+ )
+};
+
+bool process_record_user(uint16_t keycode, keyrecord_t *record) {
+ switch (keycode) {
+ case QMK00:
+ if (record->event.pressed) {
+ // when keycode QMK00 is pressed
+ SEND_STRING(SS_TAP(X_KP_0) SS_TAP(X_KP_0));
+ } else {
+ // when keycode QMK00 is released
+ }
+ break;
+ }
+ return true;
+}
diff --git a/keyboards/handwired/bstk100/keymaps/default/readme.md b/keyboards/handwired/bstk100/keymaps/default/readme.md
new file mode 100644
index 0000000000..15f86c185e
--- /dev/null
+++ b/keyboards/handwired/bstk100/keymaps/default/readme.md
@@ -0,0 +1,26 @@
+# The default keymap for bstk100
+
+```
+ (LED)
+ +----+
+ +NumL+
+ +----+
+
++----+----+----+----+
+|Tab | / | * |Back|
+| | | | Spc|
++----+----+----+----+
+|7 |8 |9 |- |
+|Home|Up |PgUp| |
++----+----+----+----+
+|4 |5 |6 |+ |
+|Left| |Righ| |
++----+----+----+----+
+|1 |2 |3 | |
+| End|Down|PgDn|Ent |
++----+----+----| |
+|0 |00 |. | |
+| Ins| | Del| |
++----+----+----+----+
+```
+
diff --git a/keyboards/handwired/bstk100/keymaps/via/keymap.c b/keyboards/handwired/bstk100/keymaps/via/keymap.c
new file mode 100644
index 0000000000..474921eeab
--- /dev/null
+++ b/keyboards/handwired/bstk100/keymaps/via/keymap.c
@@ -0,0 +1,53 @@
+/* Copyright 2021 FREE WING,Y.Sakamoto
+ * http://www.neko.ne.jp/~freewing/
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see .
+ */
+#include QMK_KEYBOARD_H
+
+// Defines names for use in layer keycodes and the keymap
+enum layer_names {
+ _BASE
+};
+
+// Defines the keycodes used by our macros in process_record_user
+enum custom_keycodes {
+ QMK00 = SAFE_RANGE
+};
+
+const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
+ /* Base */
+ [_BASE] = LAYOUT(
+ KC_NLCK,
+ KC_TAB, KC_PSLS, KC_PAST, KC_BSPC,
+ KC_P7, KC_P8, KC_P9, KC_PMNS,
+ KC_P4, KC_P5, KC_P6, KC_PPLS,
+ KC_P1, KC_P2, KC_P3, KC_PENT,
+ KC_P0, QMK00, KC_PDOT
+ )
+};
+
+bool process_record_user(uint16_t keycode, keyrecord_t *record) {
+ switch (keycode) {
+ case QMK00:
+ if (record->event.pressed) {
+ // when keycode QMK00 is pressed
+ SEND_STRING(SS_TAP(X_KP_0) SS_TAP(X_KP_0));
+ } else {
+ // when keycode QMK00 is released
+ }
+ break;
+ }
+ return true;
+}
diff --git a/keyboards/handwired/bstk100/keymaps/via/readme.md b/keyboards/handwired/bstk100/keymaps/via/readme.md
new file mode 100644
index 0000000000..15f86c185e
--- /dev/null
+++ b/keyboards/handwired/bstk100/keymaps/via/readme.md
@@ -0,0 +1,26 @@
+# The default keymap for bstk100
+
+```
+ (LED)
+ +----+
+ +NumL+
+ +----+
+
++----+----+----+----+
+|Tab | / | * |Back|
+| | | | Spc|
++----+----+----+----+
+|7 |8 |9 |- |
+|Home|Up |PgUp| |
++----+----+----+----+
+|4 |5 |6 |+ |
+|Left| |Righ| |
++----+----+----+----+
+|1 |2 |3 | |
+| End|Down|PgDn|Ent |
++----+----+----| |
+|0 |00 |. | |
+| Ins| | Del| |
++----+----+----+----+
+```
+
diff --git a/keyboards/handwired/bstk100/keymaps/via/rules.mk b/keyboards/handwired/bstk100/keymaps/via/rules.mk
new file mode 100644
index 0000000000..1e5b99807c
--- /dev/null
+++ b/keyboards/handwired/bstk100/keymaps/via/rules.mk
@@ -0,0 +1 @@
+VIA_ENABLE = yes
diff --git a/keyboards/handwired/bstk100/readme.md b/keyboards/handwired/bstk100/readme.md
new file mode 100644
index 0000000000..7247150c48
--- /dev/null
+++ b/keyboards/handwired/bstk100/readme.md
@@ -0,0 +1,35 @@
+# bstk100
+
+BUFFALO USB 10-Key keyboard BSTK100 modification by Pro Micro and QMK firmware .
+see [[FREE WING HOME PAGE]](http://www.neko.ne.jp/~freewing/) for more detail .
+
+![bstk100](https://i.imgur.com/9s5kxSB.jpeg)
+![bstk100](https://i.imgur.com/rsilkiy.jpeg)
+![bstk100](https://i.imgur.com/TuQlxat.jpeg)
+![bstk100](https://i.imgur.com/w0g6Qlz.jpeg)
+![bstk100](https://i.imgur.com/ORgbBQh.jpeg)
+![bstk100](https://i.imgur.com/1MDm3zt.png)
+
+* Keyboard Maintainer: [FREE WING GitHub](https://github.com/FREEWING-JP/qmk_firmware)
+* Hardware Supported: Pro Micro ATmega32U4 5V/16MHz
+* Hardware Availability: [BUFFALO USB 10-Key keyboard BSTK100BK](https://amzn.to/389GGtP), [Pro Micro ATmega32U4 5V/16MHz](https://amzn.to/3jePZPi)
+
+Make example for this keyboard (after setting up your build environment):
+
+ make handwired/bstk100:default
+
+Enable VIA feature in QMK
+
+ make handwired/bstk100:via
+
+Flashing example for this keyboard:
+
+ make handwired/bstk100:default:flash
+
+See the [build environment setup](https://docs.qmk.fm/#/getting_started_build_tools) and the [make instructions](https://docs.qmk.fm/#/getting_started_make_guide) for more information. Brand new to QMK? Start with our [Complete Newbs Guide](https://docs.qmk.fm/#/newbs).
+
+## Bootloader
+
+Enter the bootloader in one way:
+
+* **Physical reset button**: Briefly press the button on the back of the PCB - some may have pads you must short instead
diff --git a/keyboards/handwired/bstk100/rules.mk b/keyboards/handwired/bstk100/rules.mk
new file mode 100644
index 0000000000..1275531ef6
--- /dev/null
+++ b/keyboards/handwired/bstk100/rules.mk
@@ -0,0 +1,18 @@
+# MCU name
+MCU = atmega32u4
+
+# Bootloader selection
+BOOTLOADER = atmel-dfu
+
+# Build Options
+# change yes to no to disable
+#
+BOOTMAGIC_ENABLE = yes # Enable Bootmagic Lite
+MOUSEKEY_ENABLE = yes # Mouse keys
+EXTRAKEY_ENABLE = yes # Audio control and System control
+CONSOLE_ENABLE = no # Console for debug
+COMMAND_ENABLE = no # Commands for debug and configuration
+NKRO_ENABLE = no # Enable N-Key Rollover
+BACKLIGHT_ENABLE = no # Enable keyboard backlight functionality
+RGBLIGHT_ENABLE = no # Enable keyboard RGB underglow
+AUDIO_ENABLE = no # Audio output