Midoriya Izuku wasn't in the best mental space when the decision to send him back in time was made, but he promised he'd do his best. There were plenty of plans made beforehand, and plenty of information he had to memorise. He had to lay low, try and keep the timeline as close to the original as possible while gradually making it a better future.. not likely.
Based on a Fic prompt from the HMS Harmony Valentine's Day Fest 2022, placed in the story. In short, Viktor Krum approaches Hermione about certain rumours he overheard about Harry and herself - the conversation leads to realisations between Harry and Hermione about their feelings for each other.
"Deciding to add a touch more flair to the triwizard tournament, Fudge brings singing Valentine's back to Hogwarts. Backed into a corner by a persistent 'cupid' wanting to meet his quota, Harry is conned into sending a Valentine to the first girl he can think of - Hermione. From a HMS Harmony Discord Valentine's Day Contest 2021 prompt.