After overcoming a heart condition while with the UST Growling Tigers, he went on to become a dominant college basketball player with the Arellano Chiefs.
Arana started playing basketball at a young age, learning to shoot with a ring attached to a mango tree built by his father.
[2] He was recruited to join his high school varsity basketball team in his third year, and by that time had grown two more inches.
A year later in 2015, he played in Bicol's Regional Meet and in the Palarong Pambansa, which helped him get noticed by big colleges and universities.
[6] He used his entire residency year to continue his recovery, undergoing weekly 2D echo tests and drinking maintenance medicine – all expenses the university shouldered.
[14] He was awarded as the NCAA's Rookie of the Year along with a All-Defensive Team selection with averages of 13.4 points, 7.8 rebounds, 2.8 blocks, and 1.4 assists.
[26] In a loss to Lyceum, Arana had a double-double performance of 17 points and 24 rebounds, adding to four blocks, an assist, and a steal, in a losing effort.
[28] He then collected a career-high 29 rebounds alongside 18 points and two blocks while playing all 40 minutes and made two clutch free throws in a win over the JRU Heavy Bombers that secured them a spot in the play-in game.
[35] In his PBA debut during the Philippine Cup, he had six points, nine rebounds, three blocks, a steal, and an assist in 27 minutes of a loss to the Rain or Shine Elasto Painters.
[38] Still, he played in the fourth quarter and made clutch baskets and a crucial block on Jvee Casio to give Converge the win, finishing with 13 points and five rebounds.
[38][39] In Converge's first game of the Commissioner's Cup, Arana contributed 13 points and seven rebounds to give their new head coach Aldin Ayo his first win in the PBA.
[42] That conference, Converge won seven straight games to get into the playoffs, with their last win coming from against Rain or Shine in which he had 16 points, seven rebounds, and the game-winning shot.