Lost Rabbit (まよい兎, Ma Yoi Usagi) is the 581st chapter of the Gintama series. More of Kamui's flashbacks is seen, right before he attacks Umibouzu back then.
Kamui explains to Kagura the relationship between their mother and the Altana; she would have survived if it weren’t their father who took her away from Kouan. Back at Umibouzu's side, Utsuro is surprised that there is another being similar to him out in the vast universe. He is also curious about the expression Kouka had before dying, whether she is relieved for being able to die, or bearing hatred towards her loved one, i.e. Umibouzu for causing her death. The irate man attacks Utsuro upon hearing.
Flashback of a young Kamui and Umibouzu is seen, with the child asking the reason for his father to fall for his mother; she wouldn't be suffering if she weren’t taken out of Kouan. Umibouzu explains that he did so to protect Kouka from having to live an eternal life in solitude, though it ended up with Kouka protecting him instead. However despite all this, both of them will still make the same choice if given another chance because they would still want to have a family together. Kamui, under the impression that he is the cause of his mother's impending death, begins on his quest to become stronger.
One day Kamui challenges Abuto, who refuses to retaliate even though he acknowledges that his opponent isn't any ordinary child. Kamui was about to kick Abuto when Housen, the then leader of the Harusame’s 7th Division, stopped him. The leader praised Kamui's skills, and easily punches Kamui away with his strength just as Abuto rushes over to Kamui's side to shield him from the attack. Housen is amused at Kamui's ambition, but will also gladly take him on when the child become stronger. He also notes to himself the resemblance between Kamui and his father. Kamui, realizing both him and Umibouzu's incapabilities to save Kouka, begin to challenge Housen every now and then in order to become stronger while the 7th Division watches on.
Back at home, Kamui asked Kouka to return to Kouan with him. Kouka was surprised that Kamui has found out about her and the Altana, but replied that it was too late; she insists on staying on Rakuyou with them. A disappointed Kamui then told Kouka he would do anything to keep her alive, even if means to sever family ties. Kouka, realizing that Kamui will follow his father’s footsteps, laments the resemblance between the both. Kagura and later Umibouzu enters the house just as Kouka begin coughing out blood. Upon seeing the scene, Umibouzu questions his son the reason for his actions at that moment. Kamui then expresses his determination to surpass his father. The scene cuts back to the present, where Kamui tell Kagura that he can only continue his quest to surpass their father even though he has failed to protect their mother. As a young Kamui is seen charging at Umibouzu back then, the present Kamui proceeds to attack Kagura in a similar fashion.
Characters in order of appearance
- Utsuro: (On Kouka's final moments) What sort of face did she have when she went? Was it a look of relief at the end of an empty time that stretched on infinitely? Or was it hatred pointed at you, her loved one that killed her?
- Umibouzu: But even if I had realised that back then, I would've... Your mom would've probably chosen the same path. If she would still be able to meet you kids.
- Housen: (To Abuto) Soldier, even if it's against a child, if they point their fists at you in earnest, then you answer with your own fists in earnest. That is a man's etiquette.
- Kamui: (To Kagura) That's right. Now that I've thrown away my family and still couldn't protect that person, all I have left is surpassing that man and becoming the strongest!