In college, before he went to the United States, he played for the Ateneo de Manila University Blue Eagles in the University Athletic Association of the Philippines in 2004. However, his first season stint was cut short due to appendicitis.

Japeth bounced back from a disappointing first season on his sophomore year as he averaged 5.7 points, 5.3 rebounds and 3.2 blocked shots per contest to help lead the Blue Eagles to an 11-5 finish in 2005. He got a high 55.4 percent shot from the field for the season and he was credited with multiple blocks in 12 of the Blue Eagles’ 16 games that included a career high of seven as well as two other contest with five or more.

On his junior year, Japeth transferred to Western Kentucky University, where he is currently seeing action with the Hilltoppers in the NCAA. He was able to post eight points, eight rebounds, four blocked shots, three assists and two steals in just 32 minutes of action in 2 games, before being sidelined by injury.

Recently, Aguilar is a member of the Philippine National Team, the Powerade Team Pilipinas campaigning for the FIBA Asia as it, the team attempts to qualify for the 2012 Olympic Games in London.