The Second is a Christian, Nidaime wa Christian, 二代目はクリスチャン (1985) dir. Kazuyuki Izutsu

The story of beautiful Christian Nun, Kyoko (Shihomi) who is the object of affection for two very different men one the happygolucky Yakuza gangster, Haruhiko (Iwaki Kouchi) who is the nextinline to takeover the ragtag Tenryu Gumi gang and the other bumbling Police Detective Kumashiro (Emoto Akira). The Tenryu Gumi is a collection of misfits and other troublemakers but are relatively peaceful due to their Christian beliefs. Their bitter rivals were the more traditional Kuroiwa Gumi, a much more sadistic and violent group led by godfather Kuroiwa (Murota Hideo).