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Futuristic Edo is no longer fun for a samurai, especially when the streets are filled with arrogant alien beings. Wielding a wooden bokken, Gintoki refuses to be moved by the invaders and will do whatever it takes to make a quick buck. The unlikely silver-haired hero is late with his rent, as usual, and his rush to avoid his landlady leads him to the sakura blossoms in the park. However, his flower watching and a delightful picnic turns into a violent game of Jan-ken-pon against the Shinsengumi! Can Kagura beat the champion Sougo as Gin tries to out-drink Hijikata, or will rebellious Zura’s giant mecha appearance put an end to all of their fun?
Gintoki Sakata, Kagura, and Shinpachi Shimura continue to scrape together a living as the freelance jack-of-all-trades group Yorozuya in Edo while living among the several odd humans and aliens that inhabit the peculiar metropolis.
In the "Love Potion" story arc, a strange incense causes the people who smell it to fall in love with the first person they see. Tsukuyo tries to collect the incense, but the smoke affects her. The Yorozuya and the entire district fall under the love potion's influence.