Becoming an Elementary Schooler in the Detective World

[A prominent reminder right up front: If you feel a character is OOC, you can curse at the author or click the X and leave, but don't take it out on the character. A thousand readers have a thousand Hamlets, and everyone interprets characters differently, as well as what counts as OOC. That's all. A little bow to all you sweethearts!] My name is Saiki Yuya. I'm seven years old, and I'm an ordinary elementary school student who just started first grade. Well, maybe I'm a little unusual. But compared with my second older brother, who's as omnipotent as God, I'm definitely ordinary. Influenced by my second brother, my greatest wish was to be a perfectly ordinary elementary school student. Then, when I started first grade, two transfer students joined our class. My world started getting weird. A bow tie that can imitate any voice, shoes that can kick a soccer ball like a rocket launcher, a skateboard that can catch up with a car, a belt that can serve as a bungee-jumping safety rope... Edogawa-kun gets new toys every day. I'm a little jealous. Running into crimes when I go out, though? No thanks. So I'm only a little jealous. Later came the unscientific tennis, unscientific basketball, unscientific card games, unscientific deductions... Edogawa-kun, standing there dumbfounded, how can you have the nerve to call other people unscientific? Reading notes / content warnings: 1. The blurb is in first person; the main story is in third person. 2. The crossover works are mostly older anime and manga. The author may add more at random, depending on their mood. 3. The protagonist is not an elementary school student in the usual sense. 4. Some characters may be OOC. 5. The main story has no CP, but the bonus chapters have a romance. The male lead is already decided: Kunimitsu Tezuka. 6. This is a crossover anime world. Details may be changed as part of the author's own worldbuilding, so please don't overthink them. 7. Slice of life. The author's writing is at an elementary school level, with no logic and a diary-like style. (Hides behind a pot while holding it over their head. I'm trying hard to write an actual plot, sob.) A little explanation about the male lead: This is the author's personal indulgence. He's my favorite 2D character, but there have been so few stories about the Captain these past few years, sob. Because of the timeline, the protagonist is seven years younger, so you can also read it as a no-CP story. During the main story, the Captain is the older boy next door. 2021/8/18 A plug for an upcoming story: My Brother Can't Possibly Be on the Black Side! My name is Furuya Yoru. I graduated from the police academy, and I never believed in anything supernatural. Until I was reborn. Yes, reborn. I got drunk at a party celebrating Rei-nii's return from his undercover work. When I woke up, I found myself back at sixteen, when Rei-nii had just been accepted into the police academy. It felt absurd that I could live my life over again, but seeing Rei-nii happily chatting with his friends, I could only think: It's all still ahead of us. Thank goodness! I have to do something to stop my brothers from dying! Kenji-nii: saved! Hiro-nii: saved! Jinpei-nii: saved! Wataru-nii: saved! After successfully saving my brothers, I breathed a sigh of relief. Next, I just had to work with Rei-nii to take down that organization. But when I reunited with Rei-nii, I suddenly realized: Wait, something seems off about him! If you're interested, check it out in my author's profile! Please add it to your favorites~ Theme: Greet the sunshine with a smile every day