Yakisoba sauce (Otafuku) — Specifically for yakisoba
Sesame oil — Toasted, for finishing
Rice vinegar — For dipping sauces, sushi rice
Sake-mirin-sugar combo — for general seasoning
Nori sheets — For ramen toppings, sushi rolls
The picks above cover items 1, 2, 3 (via Hondashi which uses sake-style depth), 5, and 6. Add sesame oil and nori separately at any Asian grocery.
The Mirin Trap
There's a critical distinction: real mirin vs aji-mirin (imitation mirin).
Real mirin (hon-mirin) is fermented from rice, ~14% alcohol, complex sweet umami
Aji-mirin is corn syrup + flavoring, 0% alcohol, sweet but flat
US grocery stores often sell aji-mirin labeled simply "mirin" — confusingly. The Kikkoman Manjyo brand on our list is real mirin (hon-mirin). Use it.
Dashi: From-Scratch vs Instant
Instant dashi (Hondashi) is what 80% of Japanese home cooks use. It's a powder that dissolves in hot water and tastes 95% of real dashi for 5% of the work. For most home cooking, instant dashi is the right choice.
From-scratch dashi: kombu (kelp) + katsuobushi (bonito flakes) steeped in 175°F water for 10 minutes. Strain. Use immediately. This is the "real" version, used in serious Japanese kitchens. Worth learning eventually, not necessary day one.
What to Skip
"Asian sesame oil" generic brands — buy actual Japanese-style toasted sesame oil (Kadoya is the standard)
Pre-made teriyaki sauce — too sweet and artificial; make from soy + mirin + sake + sugar
Wasabi paste in tubes from Western brands — usually horseradish + dye, not real wasabi