Resembling a landed spaceship, the UFO Hotel in Chiba is one of the most unusual designs the French photographer encountered during his trip. (Photo: Francois Prost/CNN)

Contrary to what many might think, these hotels are not at all discreet or hidden. Instead, they stand out with playful architecture, vibrant colors, and unique designs that are instantly recognizable. Some hotels even feature heart or lip-shaped signs, with striking names like Hotel Passion, Hotel Joy, or Hotel BabyKiss.

"You can see spaceships, boats, and even a big whale, looking very childish," Mr. Prost shared in an interview from France. Among the approximately 200 hotels he photographed, many were designed in the style of castles, creating a diverse picture of contemporary Japanese architecture.

One prime example is the UFO Hotel in Chiba, with its shape like a spaceship that has just landed from outer space. Another equally impressive structure is the Hotel Festa Qugiela in Okayama, built in the shape of a giant whale. These designs not only attract attention but also create a unique identity for each hotel.

Designed to mimic the image of a whale, the Hotel Festa Qugiela in Okayama is part of a unique architectural tradition in Japan. (Photo: Francois Prost/CNN)

The history of these love hotels has its roots in discreet inns with private entrances dating back centuries in Japan. However, their modern form began to develop in 1958, when Japan banned prostitution.

Today, instead of being associated with illegal activities, these hotels primarily serve young couples living in small apartments or sharing homes with family. "Nowadays, they are not just for sex. The hotels also offer many entertainment facilities like karaoke rooms," photographer Prost explained. Guests can rent rooms overnight or choose the "kyukei" option (short rest by the hour).

The unique design of love hotels began to flourish in the 1960s and 1970s, as these establishments became more upscale. Meguro Emperor, one of the most famous hotels of this era, started the trend of building in the style of European castles. There were also constructions mimicking French farmhouses and even Arabian-style palaces like the Hotel Aladdin in Okayama with its distinctive onion domes.

Despite their flamboyant exteriors, the design of these hotels heavily emphasizes guest privacy. "Everything is designed to ensure you don't cross paths with anyone when entering the building. So, the entrance is different from the exit, and there might be one elevator going up and another for going down," the photographer explained.

The brightly colored Baby Kiss Hotel is located in Himeji City, Japan. (Photo: Francois Prost/CNN)

By the 1990s, this architectural style began to change as hotels aimed to attract more female customers. Additionally, new laws passed in the mid-1980s placed love hotels under police jurisdiction, leading many new establishments to opt for more subtle designs to avoid being classified as love hotels.

According to hospitality industry figures from the late 1990s, it was estimated that around 500 million guests visited these establishments annually. Currently, although the exact number is difficult to ascertain, it is estimated that there are over 20,000 love hotels operating in Japan.

Although this type of hotel also appears in other Asian countries such as South Korea and Thailand, they remain most strongly associated with Japan. Many establishments have tried to rebrand themselves as "leisure" or "fashion" hotels to avoid negative stereotypes.

Mr. Prost believes that these hotels reflect an interesting contrast within Japanese culture: between conservatism and openness in society. He argues that this architecture "says more about Japan" than famous iconic buildings. He is currently planning to publish a photo book on this topic through a Kickstarter crowdfunding campaign.