Four friends were accidentally selected to travel through time during an outing, and entered the world of the Prince of Tennis. They fought with them on the court, were happy together, lost together, and shed the sweat of youth. But in the end, it was impossible for everything to go smoothly. Misunderstandings and conspiracies came with them as they grew up. Friends also have to separate one day, so how to choose? Sacrifice yourself, sacrifice others. What will be the ending? Does the song of destiny composed with youth have an ending? Everything, just as it happens...