Gintama: Season 4, Episode 51

4 - 51: Everybody's a Santa!

Tetsunosuke has been ordered to deliver a letter for Hijikata. However, he's captured by the radical Joi Check It Out gang in the process. Tetsunosuke had concealed his identity to join the gang, but now they know that he has connections to the police. He's taken hostage as leverage over the Shinsengumi and Mimawarigumi. However, the Mimawarigumi shows no concern for the hostage and plots to place the blame squarely on the Shinsengumi. Hijikata and the other members are enraged after learning Isaburo's plans. The Shinsengumi and Mimawarigumi are now in an all-out fight.