One Piece: In the Straw Hat Pirates, My Chuunibyou Fantasies All Come True

[Traveling with the crew + recruiting Robin and Nami + Red-Hair-level mastery of all three types of Haki from the start + all kinds of bizarre abilities + massive wars]

After transmigrating into the world of One Piece, Luo Xiu discovered that he had woken up in Robin and Nami's bed, and that all the cringe-worthy things he had done in his previous life had actually come true.

[On the first day of the first lunar month, you came last in your school's track-and-field race. As you ran, you shouted, “There is only one reason for your defeat: you made an enemy of me.” The Six Paths of Reincarnation illusion is realized!]

[On the second day of the first lunar month, you put on a phone case bearing Robin and Nami's likenesses, increasing both Nami and Robin's affection for you!]

[On the third day of the first lunar month, you ran to school in the freezing snow, shouting, “I'm going to bring down the heavens!” The Five Thunder Rites: Yang Five Thunders is realized!]

[On the fourth day of the first lunar month, you went shopping without an umbrella and called your family to bring you one. After hanging up, you began forming hand seals: “Water Release: Great Waterfall Technique!” The Water Release: Great Waterfall Technique is realized!]

[On the fifth day of the first lunar month, while showering, you imagined yourself training and shouted, “Rozan Rising Dragon!” Rozan Rising Dragon is realized!]

From then on, Luo Xiu joined the Straw Hat crew as Robin and Nami's devoted protector.