Rin Tsubokura

is a Shinigami and a researcher of the Shinigami Research and Development Institute.

Appearance
Rin has a small pigtail in the front side of his hair which is secured by a red tie. He wears that standard Shinigami uniform underneath his lab coat. Rin is almost always showing a face of distress or preoccupation.

Personality
He has a fondness for candy and sweets. He is a bit clumsy.

Arrancar arc
He is mostly sent to easy missions, just like when he was sent to give Ikkaku his molars. Though he stepped on them, he put on a note saying, "These molars are invisible for idiots".

When he has to help an earth-bound soul to make a cake for his mother, he immediately offered his help apart from protests from Yumichika Ayasegawa.

The Thousand-Year Blood War arc
When Akon is arguing with Kisuke Urahara as he tries to contact Ichigo Kurosaki, Rin notes that Akon is losing his composure. Hiyosu tells Rin to begin circulating word that Ichigo is on his way to Soul Society, which he does. When he receives a message that transmitter swords will be placed at every battlefield, Rin then sends out a message to all the Shinigami in Seireitei that Ichigo is currently heading for Soul Society. He then divulges that the Quincy are somehow unable to steal his Bankai, which was confirmed by the Research and Development Institute. When their building is attacked by Jidanbō Ikkanzaka, Rin stabs Hiyosu as the latter tries to seal off the area, commenting "why?" afterwards.