Kyle Monangai was raised in Roseland, New Jersey and attended Seton Hall Preparatory School in West Orange for his freshman and sophomore years before transferring to Don Bosco Preparatory High School in Ramsey, New Jersey. As a senior, he had over 900 rushing yards with 11 touchdowns, and 400 receiving yards with five touchdowns. Monangai was rated a three-star recruit who committed to Rutgers University.
Monangai played in five games in his first year at Rutgers in 2020 and did not have a carry. He played in 11 games in 2021 and had 235 yards and four touchdowns. He became a starting running back in 2022, starting 11 of his 12 games and running for 445 yards and two touchdowns. Monangai returned as the Scarlet Knights starting running back in 2023 and was able to take his game to the next level. He ran for 1,262 yards and eight rushing touchdowns en route to All Big-Ten Second Team honors.