Also known as: コハエース
A Type-Moon parody manga created by Keikenchi.
It stars Kohaku (Tsukihime) from Tsukihime and features characters from various Type-Moon series. It is drawn in a Chibi style, and it is a self-aware series that constantly breaks the Fourth Wall.
Carnival Phantasm included segments based on the series, and it was the focus of Type-Moon's 2012 April Fools' Day joke. Several characters from Koha-Ace have been made into Servants in Fate/Grand Order.