Note: Pleased be warned that much of the information of this page may be old and outdated, but this is how things stood in 2008.

Take the subway (Hanzomon or Ginza line) to Omotesando Station.

Go out Exit B2 (Oops B1 is actually better; you can see it on the map but it's not highlighted) and walk straight (this street is Aoyama Dori aka 246).

Turn left at the first big T intersection (Kotto Dori) where you see Max Mara on the left of the street.

Walk down Kotto Dori on the right side.

Keep your eye open for the Nikka Whisky building on the left side of the street.

When you come to it, a shop called The Blue Dog Gallery should be on the corner your right. Turn right at that corner.

Shosaikan is a few yards in on the left.

Pen Boutique Shosaikan
5-13-11 Minami Aoyama, Minato-ku
Tel: 03-3400-3377
Hours: 11:00 a.m to 8:00 p.m.
Open all year, no holidays

http://www.shosaikan.co.jp/ (Japanese)