♠ Tatsuki&Orihime
the princess and dragon

Tatsuki has known Orihime since 12 (before high school). Tatsuki is the only true friend Orihime has during those days when she was constantly bullied by her own classsmates because she of her unique orange hair. However, when Tatsuki came into the picture and protected her from the bullies, Orihime started to grow her hair again. It symbolizes the friendship between the two.

"I knew I don't have to cut it short again." - Orihime

Understanding

Next to Rangiku, Tatsuki is definitely the only person who can understand Orihime. In the manga, it was revealed that Tatsuki even knew that Orihime likes Ichigo.

Tatsuki has also noticed Orihime's strange behaviour before and after the whole soul society arc. She does not pursue into the matter because she probably knows that Orihime wouldn't say anything. Instead, she gave Orihime words of encouragement without directly referring to the problem itself. Even so, those words never fail to cheer Orihime up.

Protecting

Tatsuki has been protecting Orihime ever since their middle school days. In high school, she still acts as an older sister to Orihime, protecting her from whatever danger, even if it means risking her own life.

In the earlier episodes/chapter of Bleach, Tatsuki almost died from protecting Orihime from a hollow. Orihime, burning with rage, is determined to protect Tatsuki this time. It was the time her power was revealed.

Encouragement

Tatsuki has been a source of encouragement for Orihime. In the soul-society arc, Orihime almost gave up until she heard Tatsuki's voices in the background.

... to be continued