I imaged a loose MSX cassette titled `ハッピーフレット` (Happy Fret) with secondary title `MYSTERY GAME IV HAPPY FRET` containing the Japanese Micro Cabin/マイクロキャビン release of Happy Fret. Both sides contained the same data. This is different from versions of the software I have found catalogued elsewhere and does not mention Thinking Rabbit during loading. This game consists of a first-stage loader loaded and executed using `RUN"CAS:"` followed by a second-stage loader which is BLOAD'ed with a -0x0200 byte offset compared to the addresses stored on tape, and finally an unheadered binary containing the game itself. The code `MIC-MO16T` is printed on the Side A label and may be a catalogue number or release serial number of some kind. The code `MCC265105` is stamped on the spine of the cassette and may be a media serial number of some kind. This is a platform puzzle game with a player health bar. Many enemies deplete health on each frame where they are contacting the player. The function keys are used to activate different in-game actions displayed at the top of the screen in addition to the space bar which is used to jump.

CAS image fingerprint for the software found on both sides:
```
18K Happy Fret - Mystery Game IV (Micro Cabin) (Japan) [RUN'CAS-'] [_].cas crc32:2fc492bc md5:4f8423910760ac93739bc936049c1e30 sha1:46f6cd1ae8b177fa12f56dd88c31524aa8036c51 sha256:cedcbe67edf2b72d65bdb7fbf18e6fbbf4074c299cc8b402c8772a2b2a5d92a0 size:18271
```
Raw 24-bit stereo 44100 Hz FLAC audio was imaged using a Nakamichi BX-125 tape deck and a Steinberg UR22mkII USB ADC with Audacity under Win11 and is intended to be archival, CAS is for emulator use, and WAV is regenerated from CAS for the benefit of an actual MSX. Short filenames and long ones contain the same data.
