The Summer with Sonic and friends isn't as light hearted as it would be. Knuckles, Tails, Amy, Blaze, Silver, Shadow, Rouge, Cream, Cheese, Sally, Marine, and Mighty just don't wanna have fun with Sonic considering they want nothing to do with him as a friend anymore. Not even his brother Manic (who also came for their vacation) wanted to hang out with him. All of them were on summer vacation at a hotel near a every day theme park (which is an attraction with the hotel). They wanted to spend all summer without Sonic (who came with them) Though when they went too far Sonic felt so heart broken and was never in their sights. By the time they all feel bad and guilty especially Knuckles who actually does have a crush on him they slowly notice Sonic is not himself. He was feeling off and never coming out of the room he stayed in until most summer nights. He was even eating raw meat every day and night. Also strange things happened. They at first thought he was mad at all of them but Knuckles knows that there is something more sinister than that.
25 parts