Sadamine climbs smoothly. The ascent is gradual, predictable, almost meditative. Then, without warning, the road drops. Not a gentle descent — a drop. The elevation change hits fast, compression loads the suspension, and if you weren't ready, you're already fighting to keep the car stable while the next corner arrives immediately.

Six kilometers spanning the Gunma-Saitama border, Sadamine tests elevation timing. Not technical hairpin mastery. Not sustained high-speed flow. Just the ability to read when smooth transitions suddenly become abrupt drops, and adjust your pace accordingly. Cars with good suspension travel and predictable weight transfer dominate. Stiff, race-prepped setups that can't absorb sudden elevation changes struggle.

Character: Smooth climbs punctuated by sudden descents. Medium-speed corners with deceptive elevation transitions. Requires suspension that can handle compression without losing composure. This is a chassis compliance test — not how stiff your suspension is, but how well it absorbs surprise.