Fairy Tail (OAV)

Separate stories from the main story-flow on the series, this pieces are meant to be a funny side of the guild or set in different "universes" at all. The first OVA has Lucy working on the girl's dorm as the Cat princess which give us a look at the daily life on a normal day on the dorm while Lucy has to find a precious item on it. The second one shows the guild as a normal academy and Erza's love story which ends up in a mess since she is strong as always and really bad when it comes to love. The third installment has Erza, Natsu, Grey and Lucy accidentally travelling to the past to when they where children.

The OAVs are not "canon" stories and are more comedic/fan service in nature. The first has Lucy entering a dorm to find an item while dressed as a Cat Princess. The second has the guild recast as an academy with all the normal high-school antics. The third has Erza, Natsu, Grey and Lucy travelling to the past when they were children. The fourth has goes more in depth on the training that was done prior to the Grand Magic Games. The fifth happens halfway through the Grand Magic Games with the characters at a water park.

"Eternal Fellows" by Tetsuya Kakihara

#2: "Blow Away" by Tetsuya Kakihara & Yūichi Nakamura (eps 4-5)

特装版「FAIRY TAIL」公式サイト (Japanese)