Yuri, bless your heart dear, but you're way too honest at gift choices. The shipper is also leaking.
Don't forget to read the fine print on that "ticket" from sensei, boy. A "gift" that he'll have to pay to use in the future.
That little detail about a rando couple having matching keychains ends up being a good clue for Tsukino's birthday gift of choice for her future bf. Clever, until a chapter comes in where he visits her house for another one of those study/homework sessions and spots it. Even better if he brings his own so they match while they cram working on homework over break.