Curiously, the Canadian Copyright Database of all places may have the answer for this guy (go
here and search for "contra"). Many of Konami's entries there list the real names of the entire staff, so let's take a look at who is listed for
Contra Hard Corps.
Author: Hamada, Hidemi / Horio, Kenichiro / Karasawa, Koichi / Kobayashi, Hiroshi / Kumasaka, Syogo / Miyaoka, Kenji / Nakazato, Nobuya / Shimamura, Shinichiro / Soji, Akira / Suzuki, Kazuya / Takeda, Takashi / Taniguchi, Hirofumi / Yamane, Michiru / Yamaoka, Akira
Removing the
known names from the game's credits, we're left with Akira Yamaoka and Akira Soji. The only names left in the staff list are Akiropito and Gajokai. Assuming Akiropito isn't Yamaoka, then we can determine Akiropito is Akira Soji, and Gajokai is Yamaoka.
There's an Akira Souji credited for sound programming on
Sega CD Snatcher, as well.