Masahiro is a 13 year old boy that shoulders many expectations. Afterall, he is the grandson of the infamous Seimei. Masahiro tries just about everything but can't seem to find his talent, he can't even master his 6th sense: being able to see spirits, souls, demons. However, he IS able to see Mokkun, an ayakashi.
Masahiro's grandfather: Seimei, then asks him to run a task as an Onmyouji. Since Masahiro can't use his 6th sense well, he asks Mokkun to be his eyes and see the spirits for him. They slay the spirt successfully, and that is when Masahiro realizes that his grandfather had sealed his 6th sense, but for what purpose?
an extended description!