Take Azzahra Permatahani out of the pool and she is a bubbly 15-year-old who enjoys drawing and dancing to Ed Sheeran's Shape of You.
But in the water, the Indonesian teenager displays drive and focus that could rival that of an adult, said her coach David Armandoni.
All these traits were on show yesterday at the Singapore Sports School as Azzahra easily won the 400m individual medley in 4min 55.60sec, ahead of Thailand's Kwanmu Kamonchanok (5:01:36) and Ong Yong Qi of Malaysia (5:11:97).
It was her third gold of the Asean Schools Games (ASG) after she won the 400m freestyle and was a member of the 4x200m freestyle relay -winning team on Saturday.
More titles could be in store as she competes today in the 200m IM and 800m free but the Jakarta native, who is competing at her third ASG, has grander ambitions on the horizon.
She is competing at next week's Fina World Championships in Budapest and the Aug 19-30 SEA Games in Kuala Lumpur.
The July 23-30 world meet will be the swimmer's first time representing her country at an international senior meet. She will be the youngest of Indonesia's nine-strong contingent in Hungary, where she has qualified for the 400m IM, the event in which she is also her country's record holder (4:51:46).
"I'm happy and excited and nervous of course, as there will be so many swimmers there who are better than me," said Azzahra, whose idol is Hungary's multiple Olympic champion Katinka Hosszu.
Azzahra added: "My target is to clock a good time - hopefully below 4min 50sec."
Armandoni knows his protege's dream of lining up alongside Hosszu in the 400m IM final is a tall order, let alone winning a medal.
But the Frenchman hopes she will seek new inspiration from racing with and observing the world's best swimmers.
"She's been very serious since age 11, and she's improved technically," added the 46-year-old, who has known Azzahra for four years.
"She has huge potential."
Hosts Singapore claimed three silvers through Rhys Ng (100m butterfly), Chan Zi Yi (200m free), Charity Lien (100m breaststroke)and two bronzes from Jade Lim (100m breast) and Elizabeth Lee (100m fly) yesterday.