What-if Wonderland!!

 is a song by Argonavis. It is the second coupling song for their third single Hoshi ga Hajimaru which was released on April 29, 2020.

It will be used as the opening theme for the anime "Cardfight!! Vanguard Gaiden if".

It is written and composed by Yanagidate Shuhei and Tabuchi Tomoya (UNISON SQUARE GARDEN) and arranged by Yanagidate Shuhei.