This was the name of two ruling queens of Portugal. It was also borne by the Habsburg queen Maria Theresa (1717-1780), whose inheritance of the domains of her father, the Holy Roman emperor Charles VI, began the War of the Austrian Succession.
Due to similar-looking names like Leontine and Caroline, it has also been used as a feminine name from at least the mid-1800s onwards.
As a word, Kizuna (絆) refers to a bond or bonds & emotional ties, connection or link between people. It can also refer to a tether or a fetter.
Other characters combinations are also possible.
A known bearer of this name is the Georgian politician Chiora Taktakishvili (b. 1981).
In the English-speaking world this name is more commonly given to girls. This is due to the American actress Alexis Smith (1921-1993), who began appearing in movies in the early 1940s. It got a boost in popularity in the 1980s from a character on the soap opera Dynasty.
The feminine name Adina 3 is from the same root, but is spelled differently in Hebrew.