Yuuki in the games. In both RSE and ORAS, he is the male playable character. His female counterpart is Haruka (May). If the player plays as Haruka, then Yuuki is a friendly NPC rival.
In the ORAS remakes, he wears red/black/yellow clothes like in the original RS games. Except there are some noticeable differences: for example, his sweater and pants were replaced by a shirt and shorts.