明るい
あかるい · akarui · JLPT N5 · i-adj
bright
☀️ 明 = sun 日 + moon 月: the two lights together make bright
The kanji 明 joins sun (日) and moon (月), the two brightest things in the sky. Aka- is also the root of 赤い (akai, red) and 明かり (akari, a light), so akarui is literally light-filled: a sunny day or a sunny personality.