The inside of the Seiran gives the builder an average amount of real estate for a midtower. There's space for a 60mm cooler, 300mm graphic card, and a power supply up to 27mm in length. The CPU cutout measures 130mm by 140mm and there's a big 65mm by 140mm hole to route your cables through. The two 15mm grommeted slots might be a tight squeeze for some motherboard power cables.
The four hard drive racks that come included with the Seiran mount using a tool-less system that could be one of the best features of this case, if not for a few nagging issues. The racks themselves tended to rattle even when secured and seemed a bit flimsy. The drive clips on the other hand are very snug when fastened with a quick twist and feel very durable. Having the front 120mm intake fan pigybacking on two of the drive racks is a feature you'll either love or hate. Your drives will remain nice and cool, but having two heavy 3.5" devices cantilevered off of a plastic fan could be a little unsettling when it comes time to remove the assembly from the tower. Each drive rack is compatible with both 3.5" and 2.5" drives. But don't rejoice too soon if you have an SSD. The plastic lip on the back of the drive rack will need to be forcibly removed to clear the way to your SSD's SATA port, an issue we hope is quickly remedied.
While the Seiran's lean side panels give the case a slim frontal profile, cable management concerns arose when we took a peek behind the motherboard tray. There really was no room to speak of. A quick trip to the Raidmax product page reveals that, unlike our review unit, an updated left side panel on the Seiran offers a respectable 25mm of space for routing cables. A small divot behind the PSU may provide another nesting place for a few wires.