Yondaime Ooyamato Tatsuyuki
A member of a yakuza group gets fucked by a kindergarten sensei. Ooyamato Tatsuyaki is a waka of the Ooyamato group (He's the son and the forth head of the yakuza). Koga Yozomi is a kindergarten sensei (volunteer). He's also a good cook and does box. Rogi is another member of the yakuza. He has a daughter Reika that goes to that kindergarten. The kindergarten has lots of kids of yakuza members. Tatsuyaki went to different town (he got sent there). The first day there he met the local group of his yakuza group. At night he drank and fell asleep. A dude (Koga) showed up and took him home. They had sex. The next morning they talked for a while and then Koga went to work. So Tatsuyaki went after him. There he met Rogi who is also a yakuza and it seems that Rohi had some affair with Tatsuyaki's father. Anyway some stuff happens and Tatsuyaki ends in Rogi's bed - Rogi records their sex and sends it to Tatsuyaki's father. Koga finds out that Tatsuyaki is held at Rogi's place and goes there to retreive him. They have sex afterwards. the next day Tatsuyaki contronts Rogi and Rogi shoots him. In the end however they make peace the yakuza way - cause Tatsuyaki thinks that Rogi and his Pops can end up as a couple this way... He's kinda dumb in some ways.
Gokuaku BL
I think I've read it in different manga as a side story. It's about a yakuza head of some small group that is conected to a bigger group and a police officer in disguise. He's been working in secret in this yakuza group for 3 years. He's the first guy's right hand at this point. But one day he founds out that this yakuza head is fucking another yakuza head to get a promotion. After that the yakuza head reveals to the secret agent that he knows about him being a police officer. So the cop tries to call his boss (at the pollice station) during his yakuza work (he's supposed to watch the yakuza boss - the head of the biggest group they're part of) just to find out that his boss and the yakuza boss are bodies. So he snaps and kills them both. Then he goes back to the yakuza head just to fuck him. Then the yakuza head bacame the yakuza boss and the cop stopped with being a cop and became his right hand for real now (and sex partner I guess).
Raise wa Tanin ga Ii
Read vol. 3 ch. 12.3
Yakuza wo Shibatte Ii desu ka
Nights Before Night
Guy A has an insomnia for 10-11 years now. He loved this Yakuza Guy B but B got killed by some yakuza cause od politics (B was a son of the Yakuza boss). Anyway this dead guy's (B's) younger brother, dude C, causes trouble So He was put into A's care in order to bude C. They kinda get closer to each other. They end up as partners.
Namaiki na Ryouken no Shitsukekata
Uchi no Tantei Shirimasen ka?
Tract Porn