Shohei is a 15 year old boy who works at a struggling flower shop part-time. One day, after a solar eclipse/literal meteor shower (the shards raining down after it burns up in the atmosphere), he buys a strange plant he names Hikari II to not only save the shop, but to win the heart of his crush that the plant was named after, Hikari Momokawa. But Shohei soon discovers that the plant, Hikari II, feeds on his Life Energy, which often leaves him tired.
Hikari is the rich girl that Shohei has a crush on. 2 days before the story began, her dad dies in a yacht accident, which also takes a toll on her family's wealth. But when the meteor came to Earth, it breaks into many fragments, and Hikari manages to get a shard to sell for a really high price.
The owner of the flower shop.
The plant. Half Venus flytrap, half Butterwort, all alien. It's actually a life-form on a shard of meteor that fused with the aforementioned plant hybrid. It feeds on Shohei's Life Energy, as well as bugs and meat. And once it got big enough, it ate souls, and plans to rule the world.
Shohei's loving mother.
Shohei's father. He's often busy travelling on business to support his family.
Shohei's kid sister.
One of Shohei's best friends. He is a total blabbermouth.
Shohei's other best friend. He is the biggest of the three.
Hikari's best friend.
A ruthless motorcycle gang led by Orin Samekiba that cause trouble for everyone in Tokyo, especially Shohei.
The Strange Trio of Women
Exactly What It Says on the Tin. They are discreet characters that seem to be helping Shohei out. Or are they? All along, the answer is yes.