Banri Watanuki is a mixed blood tanuki youkai (raccoon demon). Very impulsive and outspoken, he labels himself as a “delinquent” and he is also the childhood friend of Karuta, Kagerou, Natsume and Soushi. He hates Soushi and considers him his rival since their childhood because Soushi called him “cute” and he never forgave him. He is in love with Karuta and is easily scared by Kagerou.
He is someone who does things for other people, as mentioned by his Jiiya (old butler who had taken care of him since he was very young and always makes his lunch). He decided to become a deliquent after a young Karuta decided to lock her feelings far away because her friends got scared of her yokai form. During that time she confessed that she envied Watanuki because his yokai form was cute.
He died in the demon raid. It is highly implied that he might have been the last to die due to his age in the next life.
-Second arc- 23 years later He is 13 years old. In the beginning of the second arc, he was not living within the mansion until he is introduced.
Both he and Soushi do not have any memories of their past selves or personas unlike the rest of the characters.
In this timeline, his best friend is Inugami. In fact, Inugami is Watanuki’s delinquent leader.
Watanuki is no longer bullied by Natsume, Kagerou, and Soushi. Actually, Soushi and Watanuki are very good friends in this timeline unlike in their last one.
It is later, in chapter 36, that Watanuki regains his memories and persona, but it was hinted that he grew suspicious of the others when he overheard the gang’s conversation in chapter 32 over their past lives and current plans to stop Inugami.
It was Watanuki the one who had the idea of changing the course of time in the first arc by using the power of the cherry blossom tree and send letters to the past.
The letter he wrote for the time capsule in the past was addressed to Karuta, expressing his true feelings for her and stating that no matter how many times they die and reincarnate, he will always be there to protect her.