Years ago, I'm talking almost 20 years at this point, there was a few scanlation groups who did mystery-thriller type manga like this one. Storm im Heaven, MangaScreener, etc. Many of which were single volume or only a few volumes, not too long and easy to finish on a slow day at the school computer lab.

I loved those and despaired when it became less common.

I heard about this because of the live action film based on it (Usotsuki Mii-kun to Kowareta Maa-chan: https://asianwiki.com/A_Liar_and_a_Broken_Girl), which I still have yet to see, stars the guy who played Kimihiro in the live action xxxHOLIC series.

It would be a mistake to take everything on face value here. Mii-kun is the very definition of "unreliable narrator", though as it turns out the lies he tells are far more complicated than the truth.

Mii-kun has three goals - protect Maa-chan (from herself and others), "fix" the kidnapping that occurs and end the murders plaguing the city. All of which could end horribly at any moment due to Maa-chan's instability and Mii-kun's inability to act.

Honestly I enjoyed this and am happy to have been able to read it finally.

Oh if the manga-ka seems familiar, they're also responsible for 'Bloom Into You'. ( )