Chibi's manga / #Kidnapping(2)

A police officer recognizes a sempai from high school's karate club at a bomb scene at a police box. He realizes his sempai is the bomber and goes alone without telling anyone to secure the suspect and ends up handcuffing each other together.

Pg. 1-206: Ryu is sleeping with his college professor, but doesn't feel loved, so he decides to kidnap his professor's son, Hayato, out of revenge. As it turns out, Hayato's relationship with his father is not very good, so he winds up living with Ryu.