I didn't read that much above the kiss scene in volume 3, so I'm not sure what sort of scenario they're in, but this starts just a little above that kiss. Sorry that I'm adding the conclusion of the prior fight scene. I wanted to show the mood entering into the kiss scene.
"I know that sort of thing! But I just worry about you. Can't I worry about you? Don't I have the right to worry about you?"
"Right... what are you saying, Shion?"
"You're forcing me to!"
Shion clenched his fist and hit the bookshelf.
A mountain of accumulated books toppled over. Cravat squeaked and hid within Nezumi's clothes.
"Sorry, I got so worked up... I didn't mean to yell at you like that."
"Not at all, your incited expression is rather alluring. If the opportunity arises, I'd like to see it again."
"Being together with you, I seem to frequently get agitated. It turns out I'm such an emotional person. I even scared myself."
"You've always been emotional by nature, with your emotions overshadowing your sense of reason. It's not shameful to freely go along with one's emotions. Four years ago as well, while you were still a No.6 elite, you complied with your feelings... and accepted me."
It was said with a barely audible whisper.
Shion lowered his head and leaned over. His lips lightly pressed against Nezumi's lips.
The sound of a book falling from somewhere resounded.
Nezumi lifted his head and asked "This isn't a kiss of gratitude, is it?"
"It's only a good night kiss."
"Oh... good night."
"Tomorrow I'd like to help give the dogs a fur trim. There's a lot of long-haired dogs, but Inukashi just leaves them there. Their furs' all knotted. They'll get dermatitis at this rate."
"I just got bitten. So regardless of whether it's long-haired or short-haired, I don't want to hear about the dogs."
Shion laughed and waved.
"Then good night."
"Hm, sweet dreams."
Shion disappeared behind the books. Perhaps since he wished to sleep together with Shion, Cravat burrowed out of Nezumi's clothes and followed Shion up.
"Good night kiss, was it?"
Nezumi leaned back in his armchair and gently caressed his lips with his fingertips.
"So you're a liar as well it seems."
In an instant the hunger, the fatigue, the pain from his wound all dissipated. In its place, other feelings slowly surged forth from within his body. It was difficult to distinguish whether those feelings were sorrow or loneliness.
What was this?
Suddenly he felt warm droplets slide down his cheek. Only after quite some time passed, did he realize they were tears.
I've long forgotten how to cry.
Like a soup with too much salt added.
Nezumi hugged his legs close and lowered his head. Slowly, he drank the tears that fell to his mouth.
=== End of chapter 4 ===
I apologize if that ended up being more confusing than enlightening due to the lack of context. But since I already partially translated it in a conversation with my friend, I thought I might as well finish the scene and post it.