Hachiman began asking the girls he interacted with more often.
[Ch-chocolate, Hachiman, do you want some?] — Sakura.
His first target was Sakura, but apparently, it wasn't Sakura.
So Hachiman continued reaching out, this time contacting Sakura's new friend, Hasebe.
[Did you get chocolate from another girl? Not just Horikita?]
Her reply made her sound very interested in hearing some gossip.
Apparently, it wasn't Hasebe either, despite them having once been in the same class and group.
[Chocolate? I don't even know how sweet you like it.] Karuizawa denied it.
"Then do you have Sato's contact information?" Hachiman asked.
[Sato? Why Sato? Do you think Maya would give you some?] Karuizawa seemed rather surprised. [No way. She looked perfectly normal today.]
"I found four chocolates in my desk drawer." Hachiman had no choice but to tell the truth. At this rate, was he seriously unable to identify even one sender?
[...] — Karuizawa. [Then do you want me to ask around for you?]
"I'd better ask her myself." Hachiman felt that girls might not tell the truth directly even among themselves, and Kushida had told him as much.
Some girls looked like they got along well, but actually hated each other. Yet they still acted like best friends, unable to stand seeing the other doing better than them or being more popular.
Thus, Hachiman obtained Sato's contact information.
He had added her during the Forestry Exam, but later deleted it after considering that she might have had feelings for him. He hadn't expected to add her again now.
It was a little awkward.
Still.
Hachiman: Is this Sato? I'm Hachiman Hikigaya. Can I ask you something?
Sato: Huh? Why are you suddenly contacting me?
Hachiman: Actually, I received some chocolate today, but I don't know who gave it to me.