Overlord: Blood Genealogy

Taiga, who is only in elementary school, is trained by Reij to be the heir of Japan's oldest Yakuza family.

After the death of the president, the Naito Shinjuku family tries to rebuild itself with the regional boss Kanemaru; Kanemaru has a different opinion than Reiji, who recommends Taiga to be the next president; a crack appears in the the family unity.

In order to achieve his destiny and cause, Tomonori Kanemaru sets the Naito Shinjuku family on fire and commits suicide by burning himself to death.

The Naito-Shinjuku family is divided into two groups: the group lead by Reiji, who proposes Taiga as the next president and the group lead by Akira Shiba, who is trying to rewrite history by putting Kanemaru on the spot.

Naito Shinjuku family is a hereditary organisation that can inherit family heads only, and they are Washio's pedigree.