From Nakama:

When Takagi Akira, an owner of an apartment, was in town, he ran into a scene where a man, Oodoi, saved an old man from a gang. Akira fell for Oodoi’s manly courage and took him in his apartment. Oodoi found Akira’s apartment comfy and spent time there. Akira thought Oodoi's manly act was now part of the past... But when Akira was harassed by mobs and about to sell his apartment, it was Oodoi who saved his life. Truth is, Oodoi is a yakuza and…