So, in Yakuza game terms, this is closer to the whole Nugget quest than it is to the main story.
Earlier today, news broke that Masao Ohtake’s Hinamatsuri manga will receive an anime TV series. The title is set for a spring 2018 premiere, though details on the staff and cast have yet to be unveiled as of press time.
The Hinamatsuri manga launched in Enterbrain’s Fellows! magazine in 2009. After Fellows! ended publication, the title moved to successor publication Harta. To date, twelve collected volumes have been published, with the thirteenth book set to hit bookstores on Friday.
Manga resource Baka-Updates describes Hinamatsuri as:
One night, a strange object falls on the head of Nitta, a member of the yakuza. Inside the box is a strange young girl named Hina. She has tremendous supernatural powers, and Nitta finds himself reluctantly taking her in. Her powers can come in handy for his yakuza business, but he also runs the risk of her using them on him! Not to mention, if she doesn’t use her powers, she will eventually go berserk and destroy everything around her. Nitta and Hina’s strange life together is just beginning…
Source: Ota-suke