Hello, Happy World! and OSTER Project Release 'Smiley Carol'

By Sam 26 December 2025

On December 25, Bushiroad announced a new collaboration between the mobile game 'BanG Dream! Girls Band Party!' and the OSTER project. This collaboration introduces the original song 'Smiley Carol' by Hello, Happy World! to the game.

Promotional image for Band Dream! Girls Band Party featuring Hello, Happy World! and OSTER project.

OSTER project, known for its work in jazz and rock, has written, composed, and arranged 'Smiley Carol'. The song is now available in-game.

Accompanying the song is an animated music video, which premiered on YouTube's 'BanG Dream! Channel'. The video showcases the vibrant characters of Hello, Happy World! and is available for viewing here.

Colorful illustration of five stylized characters in front of cartoon buildings with a bear mascot.

In addition to 'Smiley Carol', a cover of 'Miracle Paint' by Hello, Happy World! has also been added to the game.

Illustration of five colorful chibi characters performing on a stage with instruments and stars around them.

'BanG Dream! Girls Band Party!' is a rhythm and adventure game available globally on the App Store and Google Play. The game has surpassed 16 million users in Japan and continues to expand its reach internationally.

For more information, visit the official website or follow on X and Instagram.