Ugh, holy fuck the MC is even more of a pussy than I can imagine.
There's literally no difference between what this MC is doing and, for example, shelling out tons of cash every week for your favorite stripper or camwhore. MC is the literal definition of "beta bucks, alpha fucks", where the pretty girl has ABSOLUTELY ZERO QUALMS about taking ALL of his money (and his emotional support) and not giving him so much as a kiss, let alone access to that pussy.
If she cared about him the way he cares about her, she wouldn't take his money -- at least not without being in a bona fide relationship. At this point Chizuru is just using him -- and the MC is allowing himself to be used.
I do find this trainwreck entertaining enough to keep reading, but my comments on this are for you fellow readers: This is absolutely disgusting behavior to see. Never be like this. This is the epitome of beta male behavior. Because we're in a comic book, the author is *probably* going to give them a happy ending (of course, not a REAL happy ending, but probably just a confession and acceptance of said confession. If the author is feeling really generous, we might see ONE kiss. But this MC is certainly not going to get any pussy in this manga.) However!! If you attempted this kind of stunt in real life, you would NOT get the girl. Ever. You would throw your money away -- and she would take it, and she would appear grateful and happy, just like Chizuru -- but she will never fall in love with you over it. She'll take your money and go have sex and fall in love with someone else -- someone who doesn't act like a wimp.
Just in case you're not convinced that - to borrow from
@Kronix, that this guy is a cuck - please refer back to Chapter 1, where after getting dumped by Mami, he immediately envisions her having sex with someone else. And then, I quote you: "It's a bit exciting thinking about it, but this isn't the time to be standing, dick!" In other words, he GOT FUCKING ERECT thinking about his girlfriend dumping him and fucking another guy. And then after seeing the ad for a rental girlfriend, and then thinking again of his girlfriend with someone else, he got hard AGAIN! Then the scene closes with him masturbating, used tissues all around him, while crying into his pillow.
Then cue the next scene, where he hands Chizuru 40,000 yen -- that's $400 -- for their date. That's just as expensive as an actual hooker -- and honestly, at this point, a real prostitute is more honest than Chizuru, because at least then you'd be getting SOMETHING for your money. What is our MC getting out of this arrangement exactly? Nothing. He's tricked himself into believing that somehow, if he puts enough "nice guy" quarters into the Chizuru gacha machine that eventually sex is going to fall out. Maybe it'll work out that way in a manga because the author wants to make people happy, but I am telling you guys, it does NOT work that way in real life.