Daisuke

Daisuke is the most optimistic crew member. He is often enthusiastic about his duties and retains said enthusiasm after the crash. However, despite his preppy exterior, he later in the game drunkenly confesses to Jimmy (as the the alcohol content of the mouthwash had caused this after he drank too much) that he struggles to find meaning in life. He occasionally fantasizes over women and has an affinity for sugar, arcade games[2], and thrifting clothes[3].

He is helpfully unhelpful on occasion and seeks approval from the other crew members, especially Swansea and Jimmy. He is passionate about helping his crewmates, expressing concern when Anya locks herself in the medbay in Chapter 11. Despite it being dangerous, Daisuke willingly goes into the collapsed vent in the utility room after being manipulated by Jimmy to think that it is safe, and that he would make Swansea proud. He is airheaded and ditzy, and is noted by Swansea to be thick-skulled and a "useless ray of goddamn sunshine". As a result, he expresses a feeling of being useless, as proven by his desire for approval. In grim conversations and situations, Daisuke prefers to remain silent.
(description from his wiki)

For him we have less of a specific idea for him. We mostly just want him to sound like an teenage boy/young adult. Nothing to exaggerated.