妹 is the single character title for a younger sister.

In colloquial Japanese speech, this can be a way to say, darling, dear, honey, or my betrothed (only used when referring to a woman).

In Japanese, this can be the female given name Mai.

In Chinese, you will generally see this used in double form, “妹妹” or “mei mei” when referring to a younger sister.

兄姉 means “brother and sister,” in Japanese.

There's no perfect way to say it in calligraphy, but this is probably the best way.

黑闇女 is a Buddhist title that means “dark sister,” “dark one,” or “dark woman.”

There are two sisters:
One is the deva, 功德女 (“merit” or “achieving”), who causes people to acquire wealth.
The other is the “dark one,” 黑闇女, which causes people to spend and waste.

These sisters always accompany each other.

This Japanese term means “Sisterhood,” “Sisterly Love,” or “Sister Love.”

姉妹 is a Chinese, Japanese Kanji, and old Korean Hanja title for sisters.

Please note: It's kind of an uncommon title for a wall scroll.

This literally means “sister flowers,” but it is really a way to say “soul sisters” like “soul mates.”

手足情 is the love between siblings.

When you love, protect, care for, and have a deep bond that only brothers or sisters can.

The actual translation is “Hand and Foot,” but the relationship between brothers or sisters is like that of hands and feet. They belong together and complete the body. Even though this says “hand and foot,” it will always be read with the brotherly and sisterly love meaning in Chinese.

Note: During the past 20 years, the “One child policy” in China is slowly making this term obsolete.

心の姉妹 is “heart of sisters,” “soul sisters,” or “sisters of the heart.”

This can be used for actual sisters to celebrate the heartfelt love they feel.

It can even be used by two women who feel a connection as if they are sisters.