Happy Sugar Life is a love story that is like no others. If I had to summarize it in just a sentence: The Inner Workings of a Yandere, It's all sorts of morally f**ked.
The Yandere archetype is one that is often played for jokes in most stories. If Yuno Gasa from Future Diary, pioneered the Yandere archetype in mainstream anime. The main character, Satou Matsuzaka, refinds it in this one. I really enjoy stories that explore unconventional relationships and characters. Happy Sugar Life managed to scratch that itch for me.
Almost every character is twisted in the head. They all have some warped perception of what "love" is. There is only one "Normal" person in the story. Safe to say she becomes the catalyst for the second half of the story.
Major spoilers:
She fucking dies yo. The only somewhat normal person is killed by our MC. It's a twist that I saw coming but was still got like "YOOOOOO, No way! She really just did that!?!". This is where most people end up dropping out.
Reading this manga is like going on a rollercoaster ride. It lulls you in with what seems to be a safe and cute Yuri premise, before dropping you down into a ride with all sorts of emotional twists and mental loop-de-loops. The ending can only be described as... Bittersweet. While it is not the ending that I was hoping for, It is a fitting ending for this wild ride.
Its a sweet love story in a f**ked up way. The writing, while not being incredible, is better than what the other reviews are saying it is. This is definitely not everyone's cup of tea. If you don't like the Yandere trope then don't touch this with a ten-foot pole. If you want a psychological thriller or just a morally SPICY love story, this is for you.