One thing that makes SasuSaku work is their compatibility. Sakura is hot-headed, while Sasuke remains cool and stoic. Sakura shows many emotions while Sasuke shows few. And yes there are points when he shows emotion. In other words they're Yin and Yang.

Complementary but not opposing.

This is the meaning from Wikipedia

Yin 陰 or 阴 Noun ① [philosophy] negative/passive/female principle in nature ② Surname Bound morpheme ① the moon ② shaded orientation ③ covert; concealed; hidden ④ ⑦ negative ⑧ north side of a hill ⑨ south bank of a river ⑩ reverse side of a stele ⑪in intaglio Stative verb ① overcast ② sinister; treacherous

Yang 陽 or 阳 Bound morpheme ① [Chinese philosophy] positive/active/male principle in nature ②the sun ④ in relief ⑤ open; overt ⑥ belonging to this world ⑦ [linguistics] masculine ⑧ south side of a hill ⑨ north bank of a river

The funny thing is that their gender roles are switched.

Yin, the female side represents Sasuke, who is hidden, negative, the moon, (I feel like Naruto is the Sun, Sasuke is the Moon, and Sakura is the Stars.) , who can also be quite sinister.

While Sakura represents Yang, the male side, due to her positivity, in relief (she is a medic), and is open about her feelings.

They just fit perfectly.

By CherryblossomJelly