Akihito Hayashi is a Japanese composer and sound designer who worked on the soundtracks to many TOSE games around 1989, and continued to work with them during the early 90's. He may have also did sound programming for TOSE. His real name was never credited, but the Canadian Copyright Records give his real name.
His style can usually be recognized because he uses very identical (sometimes the exact same) drum loops.
Akihito wrote in 6502 assembly in TOSE's sound driver.
Because Hayashi worked for TOSE, a company that basked in its secrecy, the few games he was lucky enough to be credited in required him to use aliases.
In Kyotaro Nishimura: Hokutosei no Onna, he is credited as 林 音人 (Hayashi Otohito), which is a play on his first name Akihito, as well as the translation of the given name literally means "sound person".
In Osomatsu-kun, he and the other sound designers are listed under ホスピタル がっきたい or "hospital instruments", and so he uses the moniker こおりまくら はやし (Koorimakura Hayashi), the first word being the Japanese word for "ice pillow".
In Knight Gundam Monogatari 2, he is credited as サル・はやし (Saru Hayashi). There are two different translations, and which one was intended is not clear. Saru is the Japanese word for "Monkey", but it is also the Japanese localization of the name Sal.
In the game Battle Unit Zeoth, the game's staff roll does not list any audio staff. However, if one looks in the game's ROM, the following text can be found along with the rest of the credits:
MUSIC COMPOSER MR.HAYASHI
It is possible Jaleco removed this name (as well as the sound programmer credit) from the game's staff roll at the behest of TOSE.