First Date!? Hell's Zoo is the 14th episode of the Katekyo Hitman Reborn! anime.
Reborn convinces Tsuna to go to the zoo with Kyoko as a break. Tsuna is glad to finally able to be alone with her. His ideal "date" does not go as planned; however, as he runs into his friends in the zoo, who are causing all sorts of trouble. As Tsuna drags Kyoko all over the zoo trying to prevent her from noticing the others, Gokudera gets into a fight with some delinquents. Thus, leading to an explosion that broke the lions' cages. Realizing that all of his friends are here, Tsuna runs off thinking he might just get away from the madness. That was until he was trapped by herd of 5-6 lions of mix sex. Having ran into these lions, the head lion bypasses him completely and goes straight for Kyoko, which promptly Tsuna goes to the rescue. He jumps in front of the lion who gets punched by Kyoko's brother, who this entire time wanted to fight lions and bears, knocking the lion out cold. Gokudera attacks the other 2 lions knocking them out two, Bianchi also steps in, which we all know by now Gokudera promptly had a stomach ache upon seeing her.
After the fight with the lions, Reborn steps in on top of a hippo he befriended, in his master Pao Pao outfit (named "rhinoceros elephant" in Japanese) claiming the reason why everyone was here to pick out an animal Tsuna can use like Enzio and Leon, which Tsuna takes with great surprise, because not only was everyone here trying to help him, Kyoko also was here to help him. After some explain, they came to an agreement/ joke, Tsuna would be given a lion, and that apparently Reborn can talk to animals. Saizo the hippo tells Reborn that the real reason all the animals escaped is because Lambo went crazy with his grenades and destroyed all the cages. He then gets surrounded and runs off with I-pin in close pursuit. Haru then picks up a king cobra as a option for his decision, which the king cobra explains that all the animals are at the amusement park while he [the cobra] was left behind because he was too slow. It was then that the people at the amusement park start panicking that the animals are there, and Reborn puts all the work on Tsuna on cleaning it up.
While in that mess, Lambo and I-pin go on the spinning cup ride, and come off dizzy, that was when Lambo pulled out the 10-year bazooka and switched both Lambo and I-pin with their future selves. The cleaning-up process starts with the penguins with Kyoko's brother raging in the back round about fighting bears. Bianca then "recognizes" older Lambo as Romeo and proceeds to attack him with the cobra. Things go way down south as the gang attempts to capture the animals, hitting a few snags here and there. Eventually, Yamaoto leads the way with all the animals in tow. Unfortunately, Shimatta, the only Red Panda that can Zen meditate, also escaped but did not return, AND it is meditating on a roller coaster rail, with a roller coaster already going that could crush him at any second! Tsuna is then shot with a Dying Will Bullet and saves the panda... not long after he gets knocked off the railing, and get shot from the Spring Bullet and bouces himself and the panda to safety.