"Shiwa" tells the story of a boy and girl who fall in love at an early age, following them as they grow old. As time goes on, the two vow to enjoy the time they have together and promise to only smile when the other passes away. The song's title, "wrinkle", is a gentle reminder that time can not go back, and that the story of their love has been etched in their face with time. This song is buzzG's 31st work, and it has entered the Hall of Fame. It is featured on buzzG's album AMPLOID and the EXIT TUNES compilation albums GUMitia from Megpoid and THE BEST OF GUMI from Megpoid.