The anatomy is a liiitle weird on this one... ah well
Lieutenant of the 2nd Division, Hayashihara Aiko. She is the head of the Onmitsukidō's Detention Unit, which is why she wears a tan facemask (though she generally wears it as a scarf) and a tan Obi like all members of the detention unit. Aiko's partner is Tetsutenki Daisuke.
Aiko is an outstanding Shinigami despite her tendency to mindlessly doodle on everything. She graduated top of her class in Hoho, and joined division 2 for a time when Jun was still the captain. Upon Jun's retirement she advised Aiko to get more well-rounded as a Shinigami if she wanted to promote, so she transferred to a less specialized division (5) and ranked up to 4th seat after a while. Upon the Shadow invasion, Jun took a captain position in the 2nd again and hand picked Aiko and Daisuke to replace the former lieutenant, who was killed.
Name: Hayashihara Aiko
Age: Appears to be in her mid 20s
Weight: 139 lbs
Eyes: Light brown
Hair: Dirty blonde
Build: Tall, willowy and graceful, slight musculature,
Distinguishing marks: Two amputation-like scars on both biceps
Occupation: Lieutenant. 2nd Division
Former occupation: unseated, 20th and 15th seat, 2nd division, 16th, 9th and 4th seat, 5th division
Zanpakuto: Shin (Heart), Kido type
Shikai: A deep red, twelve-inch bowie-like knife. Thin, blue venous designs crawl up the length of the blade, and pulsate like a heartbeat.
Brief personality: Mellow, down-to-earth and rather soft spoken and serious. Tends to get way caught up in work, and is extremely, almost obsessively organized and efficient. She is patient and well-tempered, and it takes a lot to annoy her or get under her skin (especially after having worked with Jun for so long). She is also very tactically-minded, though she often over-thinks things- to the point where she is often distracted when not in combat or training, so it can be difficult to get her attention. When she is off-duty, Aiko knows how to have fun, though she aires on the cautious side and likes to stay responsible and in control. Her easygoing nature makes her quite easy to get along with, though it can be difficult to stay friends with her because she is so focused on the job.