Tetsuya Sendo is a voluntary member of the Kasanoda Syndicate. Previously, he was the heir to a rival syndicate, but he disagreed with how the syndicate ran its business. After a final confrontation with his father, he ran away from home. Scared and alone, he sat on the sidewalk in the rain wondering what to do. it was here that he met Ritsu Kasanoda, who held out his umbrella to shield Tetsuya from the storm. Tetsuya instantly understood the kind of person that Ritsu was and joined the Kasanoda Family Syndicate. Ritsu considers him his closest friend.