Kawai Kawai Kanojo (Watashi) Ga Irukara, Onechan Ha Akiramemasho? (Dengeki Bunko) [Light Novel]

[Machine Translation] I'm sorry, but I can't help it. My girlfriend is cute. The reason why my stomach is churning and I'm in agony is because I have such a beautiful, cute, and sweet girlfriend. The day I decided to confess my feelings for Jonosaki Yukari, it was decided that the two of us would work alone in the librarian's office after school. I saw that she had entered the librarian's room, and I told her how I felt... But... I'm in love with you! Please go out with me! He freezes when he realizes that the girl he confessed his feelings to is a beautiful stranger, but it is Senpai who comes out of the storage room next to his... The first time you see her, you'll be surprised to know that she's a beautiful girl. What will happen to this love that starts from a misdirection?

「ハイ、センパイ。あーん、ですよ」僕の彼女は可愛い。こんなに綺麗で可愛くて甘え上手な彼女がいるなんて、普通に考えれば幸せ以外の何でもない―はずなのに、僕が胃をキリキリさせて苦悶しているのには理由がある。僕が想いを寄せる、城之崎ゆかり先輩に告白を決意したその日は、二人きりで放課後の司書室で作業と決まっていた。これぞ好機と司書室に先輩が入ったのを確認し、思いの丈をぶつける...が。「好きです!付き合って下さーぃっ!?」告白した相手が見知らぬ美少女だと気付きフリーズしていると、隣の保管庫から出てきたのは先輩だった!!「“お姉ちゃん”―告白されたので、この人と付き合うことになりました」先輩と後輩、姉と妹、あなたはどっち派?誤爆から始まるこの恋の行方は!?