Ren and Terra, were two very different people. Ren, was an Earth bender, a general in the Earth Republic. Terra was an air nomad, believing in freedom and harmony. They met in an awkward kind of way, her being apprehended for going through a private area, belonging to the military. But somehow, in that whole tragedy, they fell in love. His stern ideals slightly bent by her airy ways, and his stubborn beliefs influencing her own. It didn't take long for the couple to fall in love and marry; from there, came a family. It began with Tenshi, who was hoped to be a boy. Ren being the stubborn man he was, refused to change the name, despite it being for a male. He raised his daughter like he would a son, stern and blunt.
Not even a year later, and Terra was pregnant again. The pregnancy was rough, because Ren was being relocated, and Terra followed along. The new terrain wasn't the best environment for a woman with a big belly and swollen feet. One day she lost her balance, and only because of her bending abilities, was she able to stop from landing on her stomach. Still, there was a lot of strain when it came to her second born, and the effects were obvious when she came into the world. Lenna was born second and didn't receive as much affection as her sister. There were two sides to her, eerily silent, and terrifyingly screechy. Once she was upset, it was impossible to silence her.
Senkai was born only a year and a half later. She was spoiled and appreciated by Ten. They had the same story when it came to their names, though Ren didn't feel the need to be as hard on Sen. She was left in her own naive bubble, which caused Len to boil in disgust and envy. Her sister was far more docile than she was, and too naive for her own good. Due to the fact that Ten and Len were so close together in age, Ren expected their bending abilities to bloom at the same time. He was exuberant when Ten learned she was an Earthbender, and immediately started training her at the young age of eight. He gave Len until this time (age eight), and was beyond disappointed when it turned out she was a nonbender. His disappointment vanished quickly enough, when Sen discovered her Airbending abilities at age seven.
Meanwhile, their mother was growing bored of this lifestyle, missing her old and pure ways. She began to grow exhausted of Ren's stony morals, and stiff behavior. It was when Ten was twelve, Len was eleven, and Sen was 9.5 that their mother vanished into the night. This left Ten to take on many responsibilities and causing her already mature attitude to grow beyond her years. Len, was left to find for herself, Ten deeming her old enough to do so. This fed Len's slightly unhinged personality. Sen, was naive as ever, and fell behind in her bending lessons which left her weaker than her sisters. Ten was already quite advanced, while Len was mastering the art of knives.
Their father fell deeper into the depression as the years passed on, having Terra leave him, really tore him apart inside though the girls didn’t know it. Ren waited it out, wanting to make sure his daughters were old enough to care for themselves, before removing himself from the world completely. By this time, Ten was still in highschool, nearing graduation at the age of 18. Len, was right behind her sister in graduation, surprisingly graduating with grades equal to, Ten’s. Sen had just completed her second year of highschool, so she was the only one Ten needed to worry about.
Now with their father gone, Ten was head of the household, and made the decisions. Their current home was filled with miserable memories, and she wanted to move to a place where they carried some type of relations. So, despite him being a long lost cousin, Ten decided to relocate the family to Republic City where their cousin Nadia resides.