The longest day is the one hundred twenty-ninth chapter of the Tokyo卍Revengers (Manga).
When Takemichi asks the leader of the group how many Tenjiku members they are facing, he replies that there are a hundred. Unexpectedly, he orders all of them to leave, saying that he would not do something as cowardly as pitting a hundred people against four. Instead, all four of them will fight him; his self-assurance angers Smiley, who challenges him to a one-on-one fight. The Tenjiku member introduces himself as Kakucho, one of Tenjiku's Big Four, and Smiley swings a punch.
Meanwhile, Mikey sits by an ocean port, playing with his taiyaki. Soon after, a person asks about the fate of the taiyaki, introducing himself as Izana Kurokawa. Izana compliments Mikey's CB250T, then says he will see Mikey again sometime, leaving Mikey confused about the unusual interaction.
Meanwhile, in Yokohama, Kakucho and Smiley fight, with both of them seemingly evenly matched. Just before Smiley gains the upper hand, Kakucho grins; Smiley knocks down Kakucho by diving at him with his legs outstretched. As Kakucho lies on the ground, Smiley tells him he is as strong as he expected Tenjiku's Big Four to be. As the group prepares to go back to Tokyo, Takemichi says that Kakucho seems familiar, but brushes it off.
Just then, Kakucho shouts in frustration, evoking Takemichi's memories of his childhood friend, who screamed after defeat. Takemichi realizes that Kakucho was his elementary school friend. Kakucho tells Takemichi that he lost purposely in order to talk to him privately; Takemichi tells Kakucho he has not changed, as he still picks fights. Kakucho responds that Takemichi has not changed either, calling him his hero. He tells Takemichi he has devoted himself to Izana Kurokawa, Tenjiku's boss; in essence, they are now enemies. He begs Takemichi to save Izana.
Characters in Order of Appearance
Takashi Mitsuya vs. Kanji Mochizuki
Second Division vs. Tenjiku
Nahoya Kawata vs. Kakucho
Takemichi Hanagaki and Seishu Inui vs. Yasuhiro Muto
Tokyo Manji Gang vs. Tenjiku
Chifuyu Matsuno vs. Kanji Mochizuki
Hakkai Shiba vs. Ran Haitani
Souya Kawata vs. Rindo Haitani
Takemichi Hanagaki vs. Kakucho
Seishu Inui vs. Hajime Kokonoi and Yasuhiro Muto
Souya Kawata vs. Tenjiku Leaders
Tokyo Manji Gang vs. Kakucho
Manjiro Sano vs. Izana Kurokawa
Takemichi Hanagaki vs. Tetta Kisaki