Please let me pay with 〜せてください
Grammar Explanation: Please let me with 〜させてください

To help ease Kanami’s sorrow due to her situation in life, Makoto offers to let her rent time with him as an older brother. On the first rental, Kanae says she will pay him, something Makoto wasn’t expecting.
- 叶実:
- 「レンタルはお金
( がかかります」- “A rental costs money.”
- 「だからお金
( 払( わせてください」- “Therefore, please let me pay.”
- “A rental costs money.”
The verb 払
Key Points
払わせてください asks permission to pay
払
( う becomes the causative 払( わせる, “let me pay”.〜てください turns it into a polite request: “please let me pay”.
だから ties the request to the rule
Kanami first says a rental costs money.
だから presents paying as the natural consequence.
お金
( を: the object particle is omittedA fuller version is だからお金
( を払( わせてください.In speech, を is often dropped before the verb when the object is clear, so お金
( 払( わせてください still means “let me pay money”.
The politeness fits the emotional distance
Even though Makoto did not expect money, Kanami frames payment seriously and formally.
お金
( also keeps the wording polite.