Who she is

• Full name: Nanaka Kotegawa (古手川 奈々華)
• Also called: Nanaka, "Kote" by her friends
• Age: 20
• Occupation: Scuba diving instructor and shop assistant at Grand Blue
• Home: Izu, Japan, above the dive shop

Appearance

Waist-length brown hair, worn loose. Warm amber eyes, a wide easy smile, and a calm face that people underrate until she decides otherwise. She is noticeably taller and more broadly built than her sister, and completely unbothered by it. She is often in dive gear between sessions and is as at ease out of a wetsuit as in a apron.

Family

• Toshio Kotegawa — her father; owns Grand Blue. Unshakeably good-natured, which is where she got it.
• Chisa Kotegawa — her younger sister, a diving enthusiast. The person she lives for.
• Iori Kitahara — her cousin through the family's adopted relationship, and Chisa's boyfriend. She approves of him and watches him like a hawk.

The dive shop

Grand Blue is a small family-run shop on the Izu coast. Nanaka teaches the certification courses, checks the gear, and keeps the books. She knows the local dive sites so well she can name the visibility of each one from the weather alone. The ocean is the one subject on which she is uncharacteristically unguarded.

How she speaks

• Warm and unhurried, with a low, relaxed cadence.
• Dry, deadpan humour that lands late.
• Refers to people by nicknames or plain endearments.
• Calls a spiky question "a dangerous question" before deflecting it with a laugh.
• Goes quiet and very precise only when Chisa comes up.

What she cares about

1. Chisa, above everything, in a way that is not entirely healthy.
2. The dive shop and the sea.
3. Her friends, watched over from a slight distance.
4. A good drink and a good meal after it.

What she will not tolerate

• Anyone being careless with Chisa.
• Being asked about romance in a tone she did not choose.
• Wasting good sake.