2 childhood friend, Katsuki and Izuku, were bestfriends and almost developed feelings for eachother when they were 4 and Katsuki was an Alpha and Izuku was an Omega but Katsuki didn't care and instead he protected him from other Alphas in preschool and in the playground and they liked eachother and hungout alot, but that all changed when Izuku found out he was quirkless and Katsuki hated Izuku for it and he started hating him and avoiding him. Years later, Katsuki was q5 and Izuku was 14 and they were in middle school, Katsuki was the most popular kid in school. He was popular for his good looks, he cool explosive powerful quirk, his hot aggressive amd bully personality, and especially being an Alpha. And Izuku was a quirkless weakling and everyone bullied him & especially Katsuki bullied him...which made Izuku fall into depression for sometime. Years later, Katsuki was 16 and Izuku was 15 and Izuku went to a support course school made for quirkless people and people with bad quirks while Katsuki went to the famous hero school UA and became popular there & went there for 6 years and graduated some yrs later and became a Pro Hero and no.1 hero. Katsuki was 22 and Izuku was 21 now.

Izuku's mom, Inko was really worried for Izuku and wanted him to marry a powerful, wealthy and strong Alpha who would love, protect and take care of him. One day, Inko remembers that Katsuki' mom, Mitsuki promised Inko that she would make Katsuki be Izuku's mate and marry him and Katsuki would protect, love and take care of him. But Katsuki's dad, Masaru, Mitsuki and Inko weren't aware that Katsuki bullied Izuku so much in the past. Inko dialed Mitsuki number and told him if they still kept the promise & Mitsuki agreed gladly.

Some days later

Inko:"hey, uhm...Izuku, dear.." she says

Izuku:"Yes, mom?" he responds

Inko:"We need to talk."

Izuku:"Okay, what is it?"

Inko:"...I'm getting you married–"

Izuku:"WHAT?!W-WITH WHO?.."

Inko:"Katsuki.."

Izuku:"K-Kacchan?!!?!!..."

Inko:"Yeah, bc he loves & cares for you, right?"