The Hong Kong Kowloon Treasure Murder Case File 1 - S1-E1
Continuity mistake: A mysterious man spills beverage on Miyuki's tanktop, creating a large brown stain that forces her to go change clothes. When she steps into the changing room from the urban legend, though, her clothes are pristine, the stain is entirely gone. (00:08:10 - 00:09:15)
The Hong Kong Kowloon Treasure Murder Case File 1 - S1-E1
Plot hole: The plot of the four-parter is complete nonsense even for a kid show. It is tied together by unbelievable pure coincidences; Miyuki is the perfect doppelganger of a missing model, Kindaichi randomly bumps into a high school mate who just happened to be in HK as well (!), and they both equally randomly (so they think) bump into the model who was just chilling on a park bench (so much for disappearing!), he befriends the son of the victim from 20 years before.
The Hong Kong Kowloon Treasure Murder Case File 1 - S1-E1
Other mistake: Throughout the episode, certain street signs ("Job&Piece", "Ocean Guest House") are used multiple times in different points of Hong Kong (for instance the establishing shot of the city, behind Kindaichi and his friends when they meet, during the bike chase).
The Hong Kong Kowloon Treasure Murder Case File 2 - S1-E2
Continuity mistake: Hen Ivy calls the actual Ran in disguise "Ran-san", Saki is pointing the camera at her in one shot, and his arm is all the way down his side in the next. (00:09:25)
The Hong Kong Kowloon Treasure Murder Case File 2 - S1-E2
Other mistake: Miyuki calls Kindaichi at 9:48 AM. Hearing the pink dolphin hint, they run to the Kowloon Palace statue. When at that location Saki shows him the picture, the cell phone says it's 15:24. Too much time elapsed between the two moments. (00:17:00)
The Hong Kong Kowloon Treasure Murder Case File 2 - S1-E2
Continuity mistake: Kindaichi and Saki's position keeps changing between shots when they discover the fake suicide victim at the top of the stairs. (00:19:50)
The Hong Kong Kowloon Treasure Murder Case File 2 - S1-E2
Continuity mistake: Ivy's grip on the glass shard changes between shots; at first the thumb is not visible, then the hand is positioned differently. (00:19:55)
The Hong Kong Kowloon Treasure Murder Case File 2 - S1-E2
Plot hole: An essential part of the plot relies on the fact that thanks to Saki's handheld camera, Kindaichi can examine Ran's arse dragon and therefore investigate even in her absence. But what set the plot in motion was the fact that Ran appeared in a professional modelling photoshoot displaying it. Stupidity of the girl aside, that means that the culprit never needed the girl, having HQ shots of the tattoo at their disposal. They even work for the company.
The Hong Kong Kowloon Treasure Murder Case File 2 - S1-E2
Other mistake: When Saki shows the picture of Ran's butt, the photo is taken from the right of the girl. In the scene during the previous episode, Saki was standing on Hajime's left, and he could never take that shot from that angle.
The Hong Kong Kowloon Treasure Murder Case File 3 - S1-E3
Other mistake: Saki was filming the table from his seat, and he couldn't have got close-ups of the soup bowls from the angle proposed. (00:04:45)
The Hong Kong Kowloon Treasure Murder Case File 3 - S1-E3
Plot hole: The surprise reveal of the killer doesn't make any sense, because Kindaichi gathered everyone involved in the case, and the killer very much is; they are absent for no reason, so the denouement shouldn't have even started and the audience would have to be napping not to notice.
The Hong Kong Kowloon Treasure Murder Case File 4 - S1-E4
Plot hole: Miyuki has been peacefully waiting for over a day at a stranger's house because she was told that the whole Hong Kong was under lockdown and her friends were in another location. That cover story (which would have been exposed if only she looked out of the window, people were NOT in lockdown) does not explain at all the kidnapping in the clothing stall or why she didn't have her phone or talk to Hajime at any point. She'd have to be braindead not to question even slightly what was happening.
The Hong Kong Kowloon Treasure Murder Case File 4 - S1-E4
Plot hole: The plot involves mother and daughter having a matching tattoo on their butt. This episode tells us that they had the matching tattoo since Ran was literally a child since her father himself did it. It's easy to understand that since kids, you know, grow and all, a dragon on the buttock of a 6 years-old would be quite different when they are all grown up. And it's no small tattoo and it needs to be accurate because it's a map.
Reika Hayami and the Uninvited Guest - S1-E5
Continuity mistake: The bad guy digs his fork and knife into the juicy steak, and we get a close-up of that. When he forces out a laughter at Kindaichi's statement a couple of shots later, we see the plate changed; the veggies swapped position and the cut does not match. (00:05:30)
Reika Hayami and the Uninvited Guest - S1-E5
Continuity mistake: When Reika asks everyone who got the first two questions right to stand, the imposter's cup and Kindaichi's are different from just a moment before; Kindaichi's is suddenly empty and both cups are turned (the guy's cup and plate switched side too). (00:10:20)
Reika Hayami and the Uninvited Guest - S1-E5
Continuity mistake: The bloodstains on the back of the pink shirt change throughout the episode, from the time when the victim wore it, to the various phases when the culprit is exposed. (00:19:55)
Reika Hayami and the Uninvited Guest - S1-E5
Continuity mistake: In the hall where Reika holds the quiz, the participants keep changing clothes throughout the scene depending on the camera angles.
The Alchemy Murder Case File 1 - S1-E6
Revealing mistake: When Kindaichi shifts the stage screen Miyuki is holding, her fingers are not gripping the sides in the new position. Unless she is keeping it up sticking the back of it to her palms like Spider-man, it is impossible. She does hold it normally in all the other shots. (00:01:55)
The Alchemy Murder Case File 2 - S1-E7
Continuity mistake: Miyuki and Reika are alone in the makeshift cell. When they sit on the bed after Kindaichi left them alone, the bottles on the table keep changing the direction they face between shots - just look at the "500 ml" notation, which faces the camera in 1 out of 3 bottles in the first two shots - which are taken at opposed angles - and then in all 3 bottles in close-up. (00:14:20)
The Alchemy Murder Case File 2 - S1-E7
Revealing mistake: The director is drinking alone and freaks out about to go on a murderous rage. In the shot when she realises that her snacks have been tampered with and stands up, the bottle of "Yontory whisky" she is drinking from has a different texture from the rest of the scene. The snacks themselves also change position between shots. (00:17:00)