Sikigu
Sikigu is a stationery brand from Japan, made by Taisei Shiki Mfg. 3 guides to Sikigu products. More: official site taisei-shiki.jp.
Sikigu guides and roundups
Sikigu Fumibako: Paper Letter Box With Pen Tray
Sikigu Fumibako by Taisei Shiki: a V-cut paper box for letters with a movable pen tray, sizes L 275 × 198.5 mm and S 198.5 × 137.5 mm, 66.5 mm tall.
Sikigu Pad Note: A5 Folded-Sheet Notebook, 80 Pages
Sikigu Pad Note from Taisei Shiki in Osaka: a notebook of stacked folded sheets that tear off cleanly, 80 pages, five sizes from Pocket to A4, per the maker.
Sikigu Swing Letter: Laser-Cut Rocking Greeting Card
Sikigu Swing Letter by Taisei Shiki: a 110 × 55 mm paper greeting card with laser-cut words that sways when nudged, sold with an envelope. Specs and variants.