A Man Who Cooks For Himself And A High School Girl (WN)

it might be.

“Mahiru–! Are you there–!

“Wha!? O-Onii-san!?”

She hurriedly unlocked the door and opened it to find Yuu standing there, dressed as if he was on his way home from college.

“D-D-D-Do you need something Onii-san…!?”

When Mahiru was surprised by the appearance of the person she had been thinking about until just before, Yuu offered something to her, saying, “No, I found this on the floor.”

It was the same wallet that Mahiru was using—or rather, it was her wallet.

“Uweh!? Wait, no way!?”

“I found it in front of the door, is it yours?”

When Mahiru examined the contents of her bag, she was certain that it was hers.
Perhaps she had dropped it when she was taking out her house key.

“T-Thank you very much, and sorry for the trouble!”

“Don’t worry, just be careful next time, okay?”

“Well then, see you later,” Yuu said so and turned his back to leave.
But then Mahiru, who was looking at his back, reflexively said, “P-Please wait!”

“U-Uhm…Onii-san…Don’t you find me annoying…?”

“Eh?”

As the neighbor looked at her as if saying, “What’s this girl suddenly talking about?” Mahiru continues—

“If so, please tell me right…I…don’t want to be a bother to Onii-san…”

“…? I’ve never found you annoying, you know?”

“I-Is that so? B-But you couldn’t go with Aoba-san because of me…”

“Aoba? Oh, you mean the other day? Ahh no, that was more like thanks to Mahiru, I was able to have an excuse to say no.
I don't really like going out for drinks with that guy because she has bad drinking habits.”

Yuu then added, “Well, he did come with me, in the end,” and laughed at Mahiru, who looked so anxious.

“I think I've told you before, but it helps me a lot when you come over.
I can learn new dishes, and I can snack on them too.”

“B-But…Isn’t that taking up a lot of your time…?”

“No way, I'm going to have to cook for myself whether you come or not, so I think the time it will take will be similar in the end.”

“I-Is that so…?”

“Yeah, also you said that food tastes better when you eat it with someone else than when you eat it alone, right? That goes the same for me.”

“…!”

“T-Then—” Mahiru, whose eyes widened at those words, confirmed in a slightly hushed voice.

“Can I still go to Onii-san’s place…?”

“Yeah, just come anytime you want to.
I still have a lot of dishes I want to make with you.”

“…! Y-Yes!!”

When a smile blossomed on Mahiru's face, Yuu chuckled and said, “What are you so happy about?” But even so, Mahiru felt her heart instantly lighten.