Formal — to staff
Ramen · Shop
You
すみません、替え玉をお願いするので、最初の麺は少なめにできますか？
すみません、かえだまをおねがいするので、さいしょのめんわすくなめにできますか？
Excuse me, since I plan to order a noodle refill (kae-dama), could I have a smaller portion of noodles initially?
Romaji: Sumimasen, kae-dama o onegai suru no de, saisho no men wa sukuname ni dekimasu ka? / Reply Romaji: Hai, kashikomarimashita. Men sukuname desu ne.
Reply
はい、かしこまりました。麺少なめですね。
はい、かしこまりました。めんすくなめですね。
Yes, certainly. A smaller portion of noodles, correct?
Gesture & etiquette
Hold up your hand with thumb and index finger slightly apart, indicating 'a little bit.'
Don't be overly demanding. Some shops might not offer this specific customization, or might only offer it as 'men-sukuname' (less noodles) without explicitly linking it to kae-dama intentions.