Browsing through multiple Japanese sewing blogs Marie' discovered the online pattern shop millimilli. She definitely has the advantage of actually being able to read the blogs whereas I can only look.
These patterns have been highly recommended by other sewers for their excellent fit. Simple to sew, millimilli offers clean lines and understated design for both children and moms. Their knit patterns are especially popular and a staple to any pattern collection.
Marie' already made this shirt from millimilli and I am now working on some basic knit dresses. In addition to the knit dress and basic T-shirt we also have the basic raglan sleeve T-shirt pattern. Their patterns come in a range of sizes so we will be sure to post many throughout the next sewing season.
The challenge with this pattern company is as of now they only ship in Japan. The other problem is their patterns are frequently out of stock. So although we love to share our sources this is a difficult pattern to access outside of Japan. If that changes we will be quick to update.