Tohri Nishikikouji is a new bird in Hatoful Boyfriend, though he does appear in the sequel, Hatoful Boyfriend: Holiday Star.

After you've romanced Shuu at least once (ending 9 or 10), you can pursue Tohri. His path is very specific, and there are one or two points where you can miss him if you choose the wrong option.

Start a new game and follow a path as though you're romancing Shuu -- join the infirmary staff and pick options that keep you close to Shuu. Then once you're in the second term, save before or on the day of 9/3. This is when the new content begins.

On 9/3, Shuu will be off on a business trip leaving Hiyoko and Yuuya alone in the infirmary (regardless if you lied to Shuu earlier, Yuuya will be present in the office.) Hiyoko will find a camera. Destroy it! If you don't, you won't ever meet Tohri.

Ten days later Hiyoko will find another camera and will destroy that one too. She doesn't like being watched. On 9/25, Hiyoko will go back to the infirmary once everyone has left to grab her forgotten bag. Inside you'll meet Tohri. After scolding you for destroying his camera and, he will drop his business card and leave.