First Name: Jun
Last Name: Masou
Birthdate: October 5, 1986
Birthplace: Kanagawa Prefecture (?)
Height: 5'5" [169cm]
Astrological Sign: Libra
Hobbies: Guitar, Blues Harp
PGSM Roles: Jadeite, Hanako
Official Website: Masou Jun Agency Profile

Before PGSM:
Jun had some experience modeling prior to PGSM. He also made an appearance on an episode of Ultraman Gaia.

On Pretty Guardian Sailormoon:
Jun never seemed very confident of his performance, and he even said that he was trying his best, but worried it wasn't good enough; though this could have been typical Japanese modesty ^[1].

Personally, I feel like Jun had a shaky start but had a grip on his role towards the end- I think that it helped when he had the other shittenou to play off of a bit. He also developed the devotion Jadeite has for Beryl to a new level.

Projects following PGSM:
Jun has been pursuing a music career with his band, As a sign of Human. He plays guitar, bass, and does some vocals as well.

Resources:

1 - Kirari Super Live Omake #2
Masou Jun - Wikipedia Japan [Japanese]
As a sign of Human official Website [Japanese]
As a sign of Human Myspace Page [Japanese]
As a sign of Human official blog [Japanese]