Minato Giken (港技研 Port Engineering) was a Japanese developer that was a division of Arc System Works. The company was founded by Kenichi Iwanaga (岩永研一). The company closed their doors in 1997.
The company developed two Famicom games; Battle Baseball, and Hirake! Ponkikki. The former has credits but the second one doesn't. According to one of the developers, this was due to there not being enough cartridge space. Plus, since Hirake! Ponkikki was based on a kids educational show (similar to Sesame Street), the developers probably didn't think the kids would care.