BL - Inseki

After being told that his dad passed away, Souichirou returns to his childhood home, where he finds out he has two older stepbrothers, Masato, the eldest, and Kaname, the 2nd oldest. Whoever lives in the house until the end of the 1-month grace period will inherit the house, so Souichirou must to live together with his new brothers if he wants the house. But one day, he accidentally sees Masato kissing Kaname.

Keiichi has been raising his twin nephews Ren, a genius, and Takumi, a national swimmer, as his sons. On their 20th birthday, the twins confess their love for Keiichi starting the story of their relationship as both family and lovers.

Kai is in love with his older stepbrother Riku, but because Riku values the bonds of siblinghood more than anything, he plans to never act on his feelings. That is until, Riku comes home from a goukon and Kai hold back anymore.
Includes the story of Momose, a regular customer of the donut shop, and Shin, the twin brother.

Shuuji left his hometown and became a part-time teacher at a cram school. One day, Shuuji finds Kazuomi, the son of his father's mistress, standing outside of his apartment. Using Shuuji's guilty over having injured him in the past and an explicit photo, Kazuomi blackmails Shuuji in order to get Shuuji to help him continue getting financial aid from Shuuji's father.

When Yuuto's mother gets remarries, Ryuusei becomes his older stepbrother. Ryuusei is the ideal older brother. He helps Yuuto, spoils him a lot, and their relationship is great. But when Yuuto comes home earlier and sees Ryuusei making out with another guy, he doesn't know how to deal with Ryuusei or his new feelings towards him.

Kimi and Natsuo are stepbrothers. They initially had a close relationship, but after Natsuo walked in on Kimi blowing another guy, Natsuo treats Kimi harshly. Despite his treatment, Kimi doesn't blame Natsuo and is actually in love with him.

Mikage and Tomoki are stepbrothers and despite their opposite personalities they have always gotten along. Older brother Mikage can't live without rules and order and younger brother Tomoki is relaxed and unrestrained. However, when Mikage is accepted into university, they can no longer contain their feeling for each other and Mikage creates new rules for them.

Kazuya will only eat food made by his 5 years older stepbrother Shiina, who is a a chef. As Kazuya grows older, he becomes more distant, leaving Shiina to wonder if he's just a bother. Shiina decides to move out, but Kazuya, infuriated, rapes Shiina. Scared of his brother, Shiina runs away from home, but Kazuya tracks him down.

When his father gets remarried, Haruki gets a 10 years younger stepbrother, Hikaru. Hikaru distances himself from anyone other than Haruki, but at Haruki's request makes a friend. After he inadvertently hurts his friend, Hikaru decides to cut out everything, but Haruki and forcefully kisses him. As time goes on, Hikaru's love for his stepbrother spirals, becoming more and more twisted.

While his grandfather recovers from surgery, family members Touru's not even close to are fighting to become his guardian since Touru will inherit his grandfather's entire fortune when he dies. Overwhelmed by the situation, Touru confides in his cram school teacher Tsukitani. Tsukitani tells Touru to organize his family meeting on Saturday and that it might be his lucky day. When Saturday come, Tsukitani shows up to his house, revealing himself to be Touru's uncle.