Title: Mahoutsukai Tai! (TV)
English title: Magic User's Club

The aliens have been defeated, and the Bell has been transformed into a gigantic cherry tree. Now, the brave Magic User's Club must reconvene to deal with a new problem. Apparently, some inconsiderate persons left a skyscraper sized cherry tree in the middle of Tokyo, and it's become a major inconvenience to everyone in the city. Even though they have no idea who could have done such a thing, the Club feels strangely responsible and springs into action. Meanwhile, a mysterious person is spying on the magic club in the form of a small boy. 

(Source: ANN)