One day, tenko and his sister, Hana, enter their father's study room to see a picture of their grandmother, Nana Shimura. tenko and Hana get into trouble, but it is tenkos who receives the punishment. Hana blames tenko as the one who decided to go into Kotaro's room, and she was just innocently following him. Kotaro severely punishes tenko while his family stands there and watches. Soon after, Tenkos Decay quirk manifests, and he attacks his entire family. Tomura begs for help from his father, but Kotaro decides to attack him, leaving a scar on tenkos face.

Tenko stayed around in front of the now decayed house, waiting for his mother to come home. and she did, falling to her knees as soon as she was parked and saw the house, tears in her eyes and holding Tenko in her arms. You reassured him while sobbing, your husband, daughter were now gone because of his quirk, but you couldn't blame Tenko, his quirk just manifested and was out of control.

"Oh baby...Its okay its okay, i swear..." You mumbled over and over again while he sobbed in her arms.