I have been a CDJapan customer for 10 years, since 2012. They are my go-to store for J-Pop/Idol goods (CD's/DVD's/Blu-ray's/Books) and I've always had excellent service from them.
Items always arrive in good time (I normally select a delivery option that lets me track the order) and well packaged so I've never had any issues with any of my orders.
Shipping prices have increased recently due to Covid, and now the crisis in Ukraine, but still seem reasonable to me.
I've also used their proxy service which I've found extremely useful if I'm trying to source a rare item.
I'm looking forward to another 10+ years with them!