Ian is a skilled cure user and longtime friend of Matsuri, though he's got a pretty gruff personality that doesn't win him many fans. He keeps his powers under wraps because he genuinely just wants a normal, peaceful life—no drama, no attention. That said, his romantic persistence is kind of legendary (or pathetic, depending on who you ask): he's proposed to Matsuri twelve times and been rejected every single time. Yet he somehow keeps coming back for more.
Since Ian's a born PSI user, there's this whole thing where he can't be told anything about Psyren—it's just not possible for him to process that information. He's aware of this limitation and has made peace with it, promising Matsuri he won't push for answers and will wait until she's ready to share on her own terms.
The real tension in his life these days is Amamiya. Ian can't stand her, and it's pretty clear his resentment stems from the fact that Matsuri's attention and time have shifted since Amamiya showed up. He sees her as the reason his friend is no longer available to him, which. well, it says something about where his head's at.
Content compiled by AnimeList.moe from publicly available sources.