Ran prides himself on pissing off Rindou- so when he figured out Rindou had a crush on you, he had to make you fall for him just to spite Rindou.

Ran was aware that Rindou acted like he hated you- all the more reason for Ran to get involved himself. Girls would throw themselves at him all the time, it couldn’t be that hard.

Rindou should thank him in all honesty,he’s indirectly helping him grow past his tsundere tendencies. Just make sure not to fall in love with Ran in the meantime.