Haruka is often very cheerful and upbeat who considered to be a bit of a railroad Otaku.
Mettie Structure ibuki (メーティストラクチャーibuki) is Haruka's custom willwear which specializes in multi-task information processing. Also equipped with stealth capabilities which is a heavy consumption on battery power.
- Haruka's surname Hoshimiya means "star" (星) (hoshi) and "temple, shrine, palace" (宮) (miya).
- Haruka got many hobbies and a great love for trains and "all kinds of things made by people".