My Girlfriend Keeps Suspecting I'm Cheating on Her

[Note] The female lead's inspiration comes from The Tale of the Bamboo Cutter.

Kaguya Taketori accidentally transmigrates to the future and discovers that she has a boyfriend named Nakahara Chuuya.

Her boyfriend has an imposing presence, reddish-brown hair, and deep blue eyes. Mature and charming, he takes meticulous care of her.

When she returns to the past, she resolutely makes the first move and wins her adorable little boyfriend's heart.

But just as she is happily looking forward to continuing their relationship, she gradually realizes that something is not quite right: [The hat Chuuya never takes off belonged to the woman he loved most.]

[When Chuuya gets drunk, he spends the whole night tossing and turning, muttering the name of his former partner.]

Kaguya Taketori's happy smile slowly turns deranged:

[You said you loved me! You actually slayed a dragon for him? We're breaking up! I want to break up!]

[Bonus Scene]

Question: What should I do if my girlfriend keeps suspecting I'm involved with someone else?

Typical answers: Buy her flowers, get her a diamond ring, let her check your phone!

Kind stranger: Hat Guy did all of that and, to prove there was nothing between them, even tried to beat up his former partner every day.

Chuuya: [Believe me! I really was trying to capture Dazai that day! Why would I ever go on a date with that striped fish?]

Kaguya covers her ears: [I won't listen, I won't listen! You're still wearing a bow tie that matches his!]

Chuuya pulls her into his arms and holds her tightly around the waist, murmuring a warning: [Can you see clearly now?]

His bow tie reflected the name embroidered on it in gold: hers.

Chuuya thought she'd finally understood, but the girl in his arms murmured restlessly, [Your waist is so slim.]

Theme: Love needs misunderstandings cleared up before it can have a happy ending.