Most people didn’t get to meet Tohri Nishikikouji until Hatoful Boyfriend: Holiday Star. Which is a shame, because man is that golden pheasant majestic. But the PS4 and Vita releases changed that, giving people a chance to romance the chukar partridge’s rival.
Well, eventually. I took to the Vita version of Hatoful Boyfriend to find love with a fine, feathered friend again, only to discover Tohri isn’t easy. (Is any relationship?) No, you have to work for amour with this avian. To be specific, you have to love a lot of other birds before you can hook up with this one.
This is because Tohri’s romance is connected to Shu Iwamine. You have to fall in love with another birdie like Okosan or Sakuya before you unlock the option to join the Infirmary Staff on April 11th. Being part of keeping the pigeons of St. Pigeonation healthy is a big part of loving Shuu and Tohri. After you romance some inconsequential bird, then earn an ending with Shuu, Hatoful Boyfriend will unlock the option to hook up with Tohri.
As with every Hatoful Boyfriend route, Tohri’s story is rather hilarious. He’s constantly trying to keep tabs on Shuu, and Hiyoko keeps getting in the way and foiling his plot. Your "meeting" with him is orchestrated because her hunter/gatherer paranoia leads her to keep destroying the surveillance devices he’s placed around the mad doctor. He isn’t interested in Hiyoko as a friend, lover, or potential test subject. He wants her out of the way because dang it, somebody’s gotta die!
Getting his heart means becoming Tohri’s partner in crime. Since you may have come to his route after some unpleasantness with Shuu, you probably won’t have any moral objections to this course of action. (Though, Hiyoko will never actually assist Tohri with his scheme.) Securing his affections is as simple as initially destroying his cameras in the infirmary to get his attention, then choosing to get in touch with him on October 10. There are only three decisions needed to get onto his route, so you’ll always win him as long as you’re accommodating to his needs.
Of course, you can only be pleasant with the pheasant in the PS4 and Vita versions of Hatoful Boyfriend. The free PC version of the route won’t be released by Hato Moa until later this fall.