Underground

Kaneki and Touka descend underground to train, and along the way he learns that Hinami is staying at Anteiku, wondering aloud whether she sleeps peacefully. Curious about the tunnels, he hears from Touka that Tokyo's ghouls dug them long ago to keep apart from humans, and that the passages run deep enough for a person to lose their way. When she announces she will teach him through a demonstration and warns he might die, Kaneki grows uneasy.

Touka lunges and buries a fist in his gut, then throws a flurry of punches that he manages to slip. She slams him to the ground, tears off his eye patch, and when he shows no real resistance, uses her boot to bend his finger back until it snaps. Warning of a deadlier blow to come, she forces him to summon his kagune, then pauses, noting the one he used against Nishiki was far stronger. Reading its shape, she identifies him as a Rinkaku type like Rize, and explains such ghouls are tough, quick to heal, and unmatched in resilience, which paired with Rize's raw strength would let him attack and defend at once.

Because a kagune cannot always be drawn during close combat, Touka tells him to build himself up through athletic drills and hard physical work, mocking his frail build when he balks. Uta then appears to deliver Kaneki's mask, mentioning that he set the eye patch on the opposite side so he could see the eye Kaneki normally keeps hidden.