The poetless poet's activites

Please help me find this BL manga I read.
Context:
Genre:BL, Zombie Apocalypse
Main Character: guy that knows how to karate? Idk if that was karate but he was part of something before the outbreak. He has a very shitty personality too.
Main interest: this guy brings a suitcase everywhere because he remembers everything about his life even the bad one, and that suitcase has a sentimental value to him

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It’s their final year of high school. Gaku’s one-sided feelings for Haru, which he&rsquo...

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