あ
A — solar plexus / fire focus
The kana あ is the requested A focus, rendered at the solar-plexus or upper-abdominal centre and given the menu's fire/digestive symbolism. Nakazono sources support A as a core vowel sound, while this exact body placement is an editorial modern synthesis rather than a classical anatomical statement.
Point 1 of 9 in Kototama Sound Body — A-I-U-E-O vowel foci
Cross-tradition overlaps
No overlapping points are registered for this point.
Sources
Masahilo M. Nakazono, The Source of Present-Day Civilization (scholarly_modern)
Modern Kototama source for the vowel/sound-rhythm system; it does not independently establish this centre coordinate.
Kototama Sound Practice as taught by M.M. Nakazono (secondary)
Identifies A as one of the five Mother/Half-Mother vowel sounds.