Matsutarou Sakaguchi is a giant roughneck man with strength far beyond ordinary people. He never uttered words like "work hard," "strive," and "dream" like the typical shounen manga protagonist. However, he is stronger than anyone and peerless in sumo wrestling. His greatest weakness is his own carefree personality. He grows into a full-fledged sumo wrestler. (Source: ANN)

Many people have fond memories of meeting a certain teenage boy in their younger years. However, their ages vary widely, and each remembers him as a teen. This story follows the intricate intertwining of their various stories and how this young man, who apparently lives outside of time, has affected each of them.

The series focuses on the main heroine Chiari Tsukikage and her friends on managing the Jewelpet Cafe. One day at the magical world of Jewel Land, Lady Jewelina entrusted Ruby the Magical Jewel Box with a mission to make friends and collect Magic Jewels. At the same time she needs to attend the Jewel Academy to do so and open a shop called the Jewelpet Cafe. However with her friends, things didn't go well as planned with several failed mishaps happened to her and the students being scared, in the point of Ruby giving up. But when she met a young girl named Chiari Tsukikage and decides to help, Ruby's life is about to change forever. Now, she and her friends now must work together for the cafe to prosper, stick together through good and bad luck as well as protecting the Jewel Box from being stolen.

After the break up of their old band, guitarist Yuki & drummer Santa decide to form a new one. They recruit bass player Towa, young guitarist Atsuro, and after much persuasion, vocalist Sakuya. Together they form Lucifer and they struggle to make it in the music business, and also to stay together. As well, they have to deal with personal issues, such as parental objections, and watching their old bands succeed ahead of them. Sakuya is the most troubled band member, as he has to deal with his tragic past, and his relationship with teenaged lyricist Aine.