First of all, if you're using equal-equal (==) then you must get rid of <= and >= (replace them by < and > respectively), or the game will not work as intended.
Second, can you have +6 affection for more than one guy? If so, it all gets much more complicated. And even more complicated if you can have strictly 6 points for more than one of them. And it becomes utterly hard when you have two boys with equal points in the lead.
If you instead have 4 different scenarios for the boys, you don't need to read any further.
If you want to have the right relationship (i.e. with one chosen lover), then you'll have to find out the best candidature, maybe something like this:
if (max(kind of array of points) == ryohei_points) and (ryohei_points > 6):
elif (max(kind of array of points) == hitoriki_points) and (hitoriki_points > 6):
##elif ...you get the drill.
For checking "equal 6, no boys over 6" you can use (maybe, didn't test it):
elif (max(kind of array of points) == 6 == mochiku_points):
For checking "i was a bitch and didn't get any boy to like me" or "i did a truly brilliant job and maintained good fellowship with all of them without going down to carnal desires", depending on what the goal of your game is, you can use
elif max(kind of array of points) == shou_points:
Previous conditions ensure that it will bother only about values lower than 6.
Only two ifs all the way through - the mom condition, which HAS to go first, and then the first condition which initiates the chain of boys' ending conditions.
If you instead like threesomes with multiple guys and one woman, well, that's probably better to keep away from because you're gonna have a heck ton-a-load of conditions - which will affect the performance on old machines.