There are people called "hosts" who can summon powerful insects to fight battles for them. If you kill a host's insect, the host goes into an incurable comatose-like state called "fallen". News of a host who was able to recover from the "fallen" spreads, and two groups race to capture her to learn her secrets.
It had the makings of an action-packed drama; unfortunately, it was presented quite poorly. Most of the anime was focused on a love triangle that was only borderline interesting. One of the characters that had the most screen time was also the least interesting character in the whole show. The love story didn't fit well with the action scenes. The plot progression was confusing.
If only they had explained the general basis for mushi in a more straightforward manner it would've been more enjoyable. Instead, almost every important detail was left a mystery to be revealed in a future episode, which left me asking, "huh?" during most of the episodes. Almost every 24-minute episode felt like an hour. This series could've been so good had it been done right.
Not recommended.
