Itadaki Kazuya

Masu is defined chiefly by his insatiable appetite. He considers almost anything edible and will continue trying to obtain food even when someone explicitly refuses him. He periodically announces plans to diet but continually postpones them.

He is remarkably desensitized to the horrors of G Ward. Procedures that disturb newly arrived prisoners barely attract his attention, suggesting that prolonged confinement has made Deadman Wonderland's brutality ordinary to him.

Masu is a Deadman and therefore has the fundamental ability to manipulate blood outside his body. His individual Branch of Sin is never demonstrated or named.

His most conspicuous physical ability is his extraordinary capacity to eat. Masu can bite and consume materials such as plates and metal bars, demonstrating jaw strength far beyond what would ordinarily be expected.

Masu is introduced among the established residents of G Ward and helps show Ganta Igarashi the bizarre social environment surrounding Carnival Corpse. He later attends the gathering held for Toto Sakigami's return.

After Deadman Wonderland is shut down, Masu receives a retrial and is transferred to an ordinary prison alongside Masaru. In the epilogue, he turns his appetite into a public career and is shown on television as a Japanese food fighter who has established a Guinness World Record.

Masaru Sukegawa is one of Masu's regular companions in G Ward and later shares an ordinary prison with him.

Minatsuki Takami frequently spends time around Masu and addresses him respectfully as Mr. Masu.

Idaki Hitara is another member of Masu's usual circle among the Deadmen.

Toto Sakigami is welcomed back at a gathering Masu attends.