Calling it now, Tooru is the head doctor and a rock human. You dont give a character that much attention and such a creative design just to have him remain as a minor love rival, especially not this late in the series. The "head doctor" was giving me Silver Chariot Requiem vibes in a few panels, and already I'm anticipating the speculation about the mysterious stand in the staircase.
Also Mitsuba makes a good point when she brings up that the child's "major accident" being just a few "light scratches" is bullshit. You don't bleed like that from light scratches, I'm pretty sure that should be death.