**Hardness**: 10

One of the gems who focuses on patrol duty. Despite their high offensive power, their toughness is second-rate and easily broken. The other gems consider them lovely and a top fashion model.

Diamond has a clear, colorless scheme yet their gem's characteristic gives them high light dispersion, thus creating rainbow reflections. They are very sparkly and blinding. They sparkle and glow even during the night, though they seem to be able to dampen it by covering part of it up. Their hair is a fluffy short-medium bob, with thick eyebrows and eyelashes. They wear either a winter or summer uniform depending on the season. They also wear standard black shoes with small bows. Like a diamond, they always wore white opera gloves with thigh-high socks.

~!On the Moon, they wear feminine and frilly outfits that often resemble dresses with puffy skirts.!~

Diamond is very friendly, kind, and gentle. They appear to be relatively calm during a battle, even when their situation isn't good. However, they are actually insecure and frustrated with their current body which, though being the hardest, shatters easily. They dislike being compared to [Bort](https://anilist.co/character/123389/Bort), although they admire their younger sibling a lot. They are perceptive regarding gems' inner feelings and relationships, though [Cinnabar](https://anilist.co/character/123384/Cinnabar) accuses them of seeing everything as some kind of romance. Despite their more gentle nature, they're very stubborn and tend to fight until they shatter in battle. From Bort's point of view, Diamond is extremely reckless.

~!When separated from Bort on the Moon, Diamond seems to display fear at the mention of Bort, signifying that there was more hostility in treatment from Bort towards Diamond and their feelings. [Phosphophyllite](https://anilist.co/character/123385/Phosphophyllite) eventually uses this to take advantage of Diamond in threatening to bring Bort to the Moon so they comply in assisting with destroying the Earth gems. Diamond mentions that they would like to turn that "little nuisance (Bort) into dust". Invading Earth proper, Diamond is immediately angry at Bort for their unwillingness to fight and their kindness towards Cinnabar. When they're able to shatter them, Diamond is darkly satisfied with their pyrrhic victory even as both Bort and Diamond fall to pieces.!~

(Source: Houseki no Kuni Wiki, edited)

In a world inhabited by crystalline lifeforms called The Lustrous, every unique gem must fight for their way of life against the threat of lunarians who would turn them into decorations. Phosphophyllite, the most fragile and brittle of gems, longs to join the battle. When Phos is instead assigned to complete a natural history of their world, it sounds like a dull and pointless task. But this new job brings Phos into contact with Cinnabar, a gem forced to live in isolation. Can Phos’s seemingly mundane assignment lead both Phos and Cinnabar to the fulfillment they desire?
 
(Source: Kodansha USA)
 
Note: Nominated for the 8th Manga Taisho in 2015.

In the mysterious future, crystalline organisms called Gems inhabit a world that has been destroyed by six meteors. Each Gem is assigned a role in order to fight against the Lunarians, a species who attacks them in order to shatter their bodies and use them as decorations. 
 
Phosphophyllite, also known as Phos, is a young and fragile Gem who dreams of helping their friends in the war effort. Instead, they are told to compile an encyclopedia because of their delicate condition. After begrudgingly embarking on this task, Phos meets Cinnabar, an intelligent gem who has been relegated to patrolling the isolated island at night because of the corrosive poison their body creates. After seeing how unhappy Cinnabar is, Phos decides to find a role that both of the rejected Gems can enjoy. Houseki no Kuni follows Phos' efforts to be useful and protect their fellow Gems.

**Height:** 153 cm (5'0)

__[Profile (Osawa)](https://osawa-inc.co.jp/women/kayanoai/) | [Twitter](https://twitter.com/kayanoai_0913) | [Instagram](https://www.instagram.com/kayanoai_0913/) | [YouTube Channel Official Twitter](https://twitter.com/_kayanomi) | [YouTube](https://www.youtube.com/channel/UC0D6qi-Gr5RW7hqOvTEKmAw)__

__Introduction:__
Ai Kayano is a Japanese voice actress and vocalist currently affiliated with Office Osawa.

__Biography:__
Kayano wanted to work in a job that would involve "healing people", leading to initially take up a course at a vocational school. She worked in the beauty industry and became interested in acting after having seen [Aria](https://anilist.co/anime/477/). While attending school, Kayano continued working in the industry and paid for her tuition.

Kayano began working at Pro-Fit in 2010, voicing two supporting characters in the original video animation [Princess Resurrection](https://anilist.co/anime/9159/). In 2011, she voiced [Meiko "Menma" Honma](https://anilist.co/character/40592/) in [Anohana](https://anilist.co/anime/9989/) and received the Best Rookie Actress award for said role at the 6th Seiyuu Awards. Kayano, [Haruka Tomatsu](https://anilist.co/staff/95890/) and [Saori Hayami](https://anilist.co/staff/95869/) performed the series' ending theme "Secret Base – Kimi ga Kureta Mono (10 years after Ver.)", a cover of a song originally sung by the band Zone.

She is often praised for her vocal range, having voiced a variety of characters such as [Mayaka Ibara](https://anilist.co/character/55137/), [Mashiro Shiina](https://anilist.co/character/61371/), [Darkness](https://anilist.co/character/89363/) and [Akari Kawamoto](https://anilist.co/character/24311/) for example, none of which one would connect to the same voice actress.

**Trivia:**
- Worked part-time at a coffee shop with [Chinatsu Akasaki](https://anilist.co/staff/107652/) before becoming a voice actress.
- She got around 100 suggestions for her nickname in the Anohana radio show, from which she herself picked out Kayanon.

Non-anime roles:
- Atago - Azur Lane
- Graf Zeppelin - Azur Lane
- Kaga - Azur Lane
- Renown - Azur Lane

[Twitter](https://twitter.com/MenzelSavanna)

[Instagram](https://www.instagram.com/tamaraveppo/) | [Youtube](https://www.youtube.com/channel/UC3EhmDaBlHLRrAUoaGJGMnQ/featured)

An Argentine voice actress.

[Official Website](https://www.rieke-werner.de/) | [Synchronkartei](https://www.synchronkartei.de/sprecher/3279/2) | [Instagram](https://www.instagram.com/strawbellycake/) | [Twitter](https://twitter.com/rieke_werner) | [Soundcloud](https://soundcloud.com/riekewerner) | [YouTube](https://www.youtube.com/channel/UCXcDQvUYX1oCtx53ueUAaEQ)

Rieke Werner, also known under the pseudonym StrawbellyCake, is a German voice actress and singer.

The Gems fight against the Lunarians, beings who attack them and use their shattered bodies as decorations. Each Gem is assigned a role, and Phos, the youngest, is assigned to create an encyclopedia of natural history.
 
Note: A promotional video that was released through YouTube in commemoration of the publication of the manga's first volume. 
(Source: HIDIVE)