A very weak story, with little to say in its favor but that it introduces a group of very interesting and charming characters, "そして五人がいなくなる" does little to keep the reader's interest in the story. The best, its attempts at humor.
The best: it introduces the characters; some attempts at humor
The worst: it becomes too boring and repetitive
Alternatives: mystery books for children? there are many. by the same Kaoru Hayamine, for example, "「ミステリーの館」へ、ようこそ" is way better than this one; "The Three Investigators", "Flanagan" (Castilian & Catalan)...
Revisiting my childhood favorite to see if it still holds up.
The best part of the series is the character, Yumemizu Kiyoshiro. This nonconforming former professor of logic who declares that the only things in life he needs are books and a sofa to read on, is still one of my favorite fictional characters down to his stupid catchphrases. Yumemizu does solve all the cases, but the mysteries in the series don't hold a candle to the Password series by the same children's book publisher, let alone Detective Conan, in their complexity or writing. This volume, the first installment of the series, is particularly mediocre except for the very beginning when the triplets first meet Yumemizu. I would have rated it 2/5 stars if it weren't for the fact that this is one of the many Kodansha Blue Bird publications that my grandmother sent to the United States when my sister and I were little.