枝, えだ
branch, bough, limb, twig, sprig, spray
猫は枝の間に隠れた。
枝, し
Counter
counter for long, thin things (i.e. swords)
猫は枝の間に隠れた。
は
Particle, pronounced わ in modern Japanese
1. indicates sentence topic
2. indicates contrast with another option (stated or unstated)
3. adds emphasis