Muasau attended Mililani High School in Hawaii, where he was a linebacker and running back.
[1] Muasau committed to playing college football at Hawaii in 2018, the lone Division I FBS offer he received.
[4] In his first career start against rival Fresno State, Muasau led the team in total tackles and also recovered a key onside kick that set up the then-game tying drive for Hawaii.
He was also named the most outstanding player on defense of the 2020 New Mexico Bowl, compiling nine tackles, one sack and an interception in the performance.
[7][8] He was also named a finalist for the Polynesian College Football Player of the Year Award, but ultimately lost out to Zach Wilson and Talanoa Hufanga.