Hiroya Tachibana is the protagonist's childhood friend, though he has grown distant from her over the years, for reasons unknown to her. He quickly joins her search for her brother once they're certain that he has gone missing.
Though Hiroya has been distant over the years, he still remains loyal and kind-hearted towards the protagonist. Before her brother went missing, Hiroya frequented Arcadia with Shiki, who was teaching him how to play. When Shiki stopped appearing in the game, Hiroya finally decides to approach the protagonist to ask about his whereabouts.
It's revealed that Hiroya has always cherished his friendship with the protagonist. He felt guilty and responsible for her getting injured in a car accident while they were kids. Once she awoke from her coma, he decided it was better to stay away from her until he felt he could be strong and dependable, which he always admired Shiki for having those qualities.
Due to the protagonist's amnesia of the accident and events around that time, she didn't understand why Hiroya had kept away from her and what had actually happened.
|Happy Ending||Merry Bad Ending|
|Use knife||Go to "Title Screen"|
|Use knife||Select "History"|
|"Hey, don’t attack Hiroya."||Head to Hiroya's Route|
|"We don’t have to rush."||Select "Chapter 7"|
|Step Back||Set Almighty's Level to 5|
|"You’re already helping me a lot."||Set Hiroya's Affection to 0|
|"I want us to work together, Hiroya."||"How about Radius?"|
|Use knife||"Don’t lose to my brother."|
|"I need to ask Radius, too."|
|"If it’s not a big deal, then tell me."|
|"I think we can be honest."|
|"You’re making me blush…"|
|"I really want to go with you guys."|
|"Hiroya didn’t do anything wrong!"|
|"I think you should do it, Hiroya."|
|"I don’t want to be separated from you either."|
|Love Interests in Period Cube|
|Hiroya · Radius · Astrum · Zain · Demento · Libera · Poyo-Poyo|