Feminism

When the First World War broke out, women found themselves filling in men's work roles, creating a demand for more practical undergarments. Manufacturers began to use lighter and more breathable fabrics. 

Source: Love Hina wikia

Crinoline; petticoat; corset; brassiere

Buddhism

end suffering through eliminating ignorance by way of understanding and seeing how dependence originates and eliminating craving, and thus attain the highest happiness known as Nirvana.

Practices include : renouncing conventional living and becoming a monastic; the development of mindfulness and practice of meditation; cultivation of higher wisdom and discernment; study of scriptures; and invocation of buddhas and bodhisattvas.

Source: Love Hina wikia

Archeology

"Well, who knows? Excavating is tricky. It's not like you will always find what you're looking for. Even if you dig and dig, there is no guarantee you'll ever find a single thing. But that's what's so great about it, you wont find the meaningful stuff unless you dig beneath the surface. So keep digging."

—Noriyasu Seta

Sources: Love Hina wikia

Umbrella of Togetherness

The Umbrella of Togetherness refers to a romantic image stemming back to when it was not considered appropriate for a young woman to be seen in public with a man who was not a family member.

The one exception to this rule was during a rainy day, when a man could offer to share his umbrella with a young maiden in the street if she hadn't one herself. This image of a man and a woman sharing an umbrella in the rain translated itself into romantic imagery that still persists through various media.


Sources: Love Hina wikia

Japanese bathing

Individuals clean, scrub and rinse their bodies outside of the hot tub, only entering afterwards for a final rinse and relaxation.

The custom is to thoroughly clean oneself with soap and rinse before entering the tub, so as not to contaminate the bath water. The tub itself is not for cleaning, but the social contact and well-being. Until the 19th century, the Japanese did not use soap, but rubbed the skin with certain herbs, or rice bran, which was also a natural exfoliant.

After soaping, the individual would rinse the soap from their body either via a shower or a filled water container/tub.

• In modern times, most homes in Japan have a bathroom which was often not the case during and before the 1970's, when public bathhouses and Hot Springs were often used instead.
• Due to varying sized hot tubs, and since swimming is part of Japanese social life, in some house holds it is common that all members of a family bathe together in a tub at the same time. Much like in public baths, sometimes guests would be invited to join a bath as part of hospitality.
• If the tub is not large enough for multiple bathers, bathing takes place in the traditional order: first the head of the family, then the men in order of decreasing age, and finally the women.
• Bath water in Japan is much hotter than what is usual in Western Culture. The temperature is usually well above 40°C due to medical literature stating that 47°C is considered bearable for men and that the heat is considered a prerequisite for complete relaxation.

Sources: Love Hina wikia