Tsugumi Project manga volume 4 features story and art by ippatu.

Leon and Doudou have only just set out for Sado when they are ambushed by a masked stranger. Could he be in league with the mysterious peddler known as Wode? In comes riding Tsugumi, who seems to have had a change of heart about going to Sado. After all, someone needs to watch over the two humans...and keep a wary eye on Satake, the party’s newest member.

The traveling companions continue their journey, which soon leads them to a haven of civilization in the heart of the wilderness. Yet, this village is no less fraught with danger, as Leon and Doudou soon discover when they get thrown into the fighting pits. Will violence prevail, or can they show the villagers a different path?

Tsugumi Project manga volume 5 features story and art by ippatu.

Leon and friends are back on the road to Sado, having narrowly survived a rocky reunion between Satake and her sister, Mikazuchi. Old wounds are healed, promises are made, and the seemingly ageless girl known as Tama becomes the newest addition to the party.

Just when things seem to be looking up, they run into a hulking, winged ape with a taste for “strange meat.” This foe may prove too great even for Satake, but Sado beckons across the sea. Is this the end of the line for the unlikely allies?

Tsugumi Project manga volume 6 features story and art by ippatu.

After finally reaching the island of Sado, Leon and company encountered the race known as the Sky People, who proved to be Tsugumi's estranged kin. The cunning Omoikane then directed them to a derelict facility in the Forbidden Zone, hinting at answers to their deepest questions about the TORATSUGUMI project and the mysteries of the past.

A search of the facility yielded both a potential cure for radiation sickness and research notes that may allow Leon and Doudou to complete their mission. Unfortunately, no sooner did they exit the facility than they were met by Omoikane's forces, setting off a desperate struggle. Which side will emerge victorious?