The character 海 means sea. It is a combination of ⺡ (from 水, “water”) and 毎 (“every”).
When used alone, the Japanese-based reading うみ is used. As part of a compound, using the Chinese-based reading, it is pronounced カイ. It has a special reading of の when used in
Is the Order a Rabbit? » Volume 1 » Page 47 (Left) » Panel 2
Chiya serves Rize her order: “Moon and Stars Reflected Upon the Sea“.
Examples of 海 read as の
Is the Order a Rabbit? » Volume 1 » Page 36 (Right) » Panel 3
Chiya’s brought ingredients to use in baked bread include plum and edible seaweed.