So.. The Red, White, Yellow, and the Detective Boys Case where Subaru (Bourbon Suspect 1/3) was introduced in episodes 509-510/files 622-624 is actually a pretty interesting case.
I paid attention to the short story and thought it'd just end up being a case where you have to know knowledge of Japanese because Conan gets a nickname Kuroshiro-kun in this case (The Black and White boy) but it's actually ridiculously layered. The case portion itself is between the beginning of the Bourbon story arc as Jodie calls Conan and informs of Bourbon, and the epilogue of the case with Subaru being introduced to Professor Agasa and then he gets to live in the Kudo residence right next door because Conan gives him the key to his apartment.
The case has no murders, it's an arsonist case of three suspects that all lived in the same apartment as the burnt victims (Kaito Sugiura and his father that are hospitalized) that claimed to be out all night, but the diary found in Kaito's burnt-down room reveals that his father fought with 'The Yellow Person/Mr. Yellow' who had been doing suspicious things every night. Conan and rest of the detective boys were supposed to investigate the suspicious person's doings because one of their elementary school classmates, Kaito, asked them to do that, but when the detective boys arrive at the residence the following morning, the entire apartment is in ruins with the three people who lived in the residence/the three suspects and Inspector Yuminaga along with other officers already on the scene.
The most impressive thing about this case are the way Gosho uses hints and clues. There are so many different clues and I missed like dozen of them. You can basically solve this case with logical thinking, picking up on clues, having knowledge on physical objects, paying attention to character statements, looking at journals, thinking whether something seems unnatural, using common sense... like wtf. Even the way the motive of the culprit came out was surprising since it's about not believing what someone claims. This case feels now completely different when I don't just look at it superficially but actually pay attention to it instead. Not to mention there are some cool hints towards the overarching story as well, which make this case worth re-reading or re-watching.
Btw I like that it's an arsonist case than just a murder case. Gives nice variety to this whole thing.