Continuation of alternative history, comedic samurai/ alien parody manga...
In this volume, a baby that looks suspiciously like Gin is left on his doorstep (mildly squeeable...Gin is really pretty adorable with children, probably because he is about at their level in terms of responsibility), the odd jobs crew is desperate for a fan, they help with a neighborhood haunted house, they vie with the Shinsengumi for a special rhinocerus beetle, and Shinpachi falls for a girl wearing cat ears.
book 52: Gin Tama, Volume 11 by Hideaki Sorachi
Shinpachi's cat-eared love turns out to be a scam artist/ thief, Gin provides transport for an alien messenger girl and ends up in the hospital..., ...where acting nurse Sa-chan (the assassin) "takes care" of him while she is supposed to be on a mission, then begins the fairly serious (for this manga) Benizakura arc where...Katsura is cut down in cold blood by Nizo the butcher who also does some serious damage to Gin, is being taken over by the "demon" sword Benizakura, and whose strings are being pulled by an old ally of Katsura and Gin who has turned to the dark side, Shinsuke Takasugi, whose goal is to destroy Edo.
book 53: Gin Tama, Volume 12 by Hideaki Sorachi
The Benizakura arc is resolved with Gin facing off and taking down sword-possessed Nizo the butcher, the revelation of some back story about Gin, Katsura, and Takasugi being raised together by a teacher who schooled them in bushido and was cut down (apparently) in the war with the aliens (and is Takasugi's nominal motivation for destroying the world where their master no longer exists), and Gin and Katsura (who was not dead but under-cover investigating Takasugi's movements) give their former friend an ultimatum that if they should meet again they would meet as enemies and in battle to the death.
book 54: Gin Tama, Volume 13: by Hideaki Sorachi
Gin and crew help a mother (read MOTHER) reunite with her son, Shinpachi and Kagura try to investigate an alleged adulterous affair, while Gin is laid up with a cold, and end up mixing with ninjas, Katsura gives an interview to a local television station about "a day in the life of a rebel", the crew helps in a dango eating contest, and Otae, Shinpachi's sister, is stolen away by Kyube Yagyu, a master swordsperson heir from a family who instructs the shogun, to follow through on a promise of marriage made when they were children. For their own individual reasons, Gin, Shinpachi, Kagura, and Kondo, Hijikata, and Okita from the Shinsengumi, all unite in a "dream team" to face the sword masters and return Otae to themselves. Oh, and simultaneously, Kondo has been promised in marriage to an alien gorilla.