Guy finds out he's an omega and feels ostrichsized. One of his friends is an alpha so he begins to distance himself because he doesn't want to get raped and become pregnant. His childhood friend seems to be going through a heat too, so he tries to approach him saying they are same, but the friend tells him to leave him a lone and flees. Pretty sure the friend is an alpha reacting to the MC, but trying to suppress himself from hurting the MC
Shounen No Kyoukai