Levi and Eren have twin children named Rivaille and Levi Junior. Levi and Eren have to go on a very long mission until they go out into the world and meet the volleyball coach, Ukai-sensei. Levi tell Ukai-sensei to take Rivaille as an adopted child and Ukai-sensei agreed and brought Rivaille to the Karasuno Mansion while Eren goes to Inarizaki's place and meets Shiratorizawa coach ,Washijō Tanji and tells him to take Levi as a child and Washijo agrees and takes Levi to the Mansion and introduces him to his other children. Ukai- sensei change Rivaille last name into Kazume Rivaille and Rivaille meet Hinata, Kageyama, Sugawara, Daichi, Yamagucchi, Tssukishima, Nishinoya, Asashi, Tanaka as the adopted brother that Ukai sensei adopted them along with Yachi and Kiyoko as his sister and Takeda as his second father. Meanwhile, Washijō Tanji change Levi last name into Inumaki Levi and Levi meet all adopted brother and only he know that he has younger twin brother. Will Inumaki Levi and Kazume Rivaille be able to meet again?