To judge a character by "a good deed with a hidden ulterior motive" he or she has done for others and see if this person is any good, in my head at least two questions needed to be addressed:
1. What is that motive, and how does the motive rival the deed?
This is important because the answer to the prompt could be simplified into a sum of "how good the deed is" and "how ulterior the motive is".
Using "Sensei saving Rin's life from situations caused by Otoha so that Sensei later can ________" as an example:
The options for ________ are:
- get free coffee for the rest of forever
- have Rin teach him how to play guitars for free
- be on a way better term with Rika and increase the chance of sleeping with Rika
- get flashed by Rin with her finally smiling this time
- increase the chance of sleeping with Rin but still wait for her to graduate to cash out all the affinity points (not happening)
- increase the chance of sleeping with Rin
- increase Rin's trust so much that she lets him stay at the dorm at night and thus you get to take advantage of a sleeping Rin
- brainwash Rin into a devoting sex slave and use her as a threesome plot device
- plan to fuck her brain out in front of HOPE before the snow returns and finally complete his assignment (baseless statement!)
*a note here is that saving someone's life is an extra finicky situation, as your subject will have a harder time denying your advances.
Your answer
should vary when facing these different scenarios, but the the point of nope is different from person to person because people weight things differently.
For some, everything is straight up additive and as long as the sum is on the good side then it's a-okay; others care if the motive is of natural progression or a schemed result; some others may tremendously outweigh either the deed or the motive. So this is a game of subjective takes without right or wrong answers until the situation goes to extreme ends.
But the more important question to me is the next one:
2. Will the character still perform the good deed when knowing already that the ulterior motive has no way of fulfilling via the deed? In a roundabout way, this is asking when facing these "a mean to an end" scenarios, does this person care more about the mean or the end?
From Sensei's recent conversation with Yumi on the beach, Sensei started as a plain bad person (cares more about the fruit of helping her) and gradually moved toward a good person (cares more about just helping her). It should be hopefully safe to assume that this attitude can be extrapolated to the case of Rin, as I am pretty biased to think that Sensei will still help her even if his actions don't land him closer to that bi pussy.
TBH, this scenario comes really close to "saving your irl crush from her abusive bf so you have a chance to be with her in the future"
if only Rin wasn't underage...You'd be insane not to contemplate on that; but if you're still willing to help her even when she won't turn to you whatsoever, then you're a good person. (a character that comes to mind is Quasimodo, but I must apologize to Quasimodo for putting him next to Sensei for the sake of comparison)
Finally, why don't we just ask Sensei himself if he's a good person or not?!