MTL - Diary of a Sturdy Immortal - Chapter 1293 explain

Happiness of the family >>>>>> World peace!? The curtain rises on another fantasy slice-of-life tale, brought to you by the “Hataraku Maou-sama!” team.

On that day, an emergency family meeting was called to order at the residence of the Kenzaki family, an ordinary family living in Tokorozawa City. A blonde beauty named Dianaze Krone, Diana for short, had appeared from a different world, in the living room of the Kenzaki family. “I, an envoy, have come to summon the Hero of Salvation, Kenzaki Hideo.”

Wait, Hideo is my dad! To think such a game-like situation would fall upon me, Kenzaki Yasuo, an ordinary high school student.

My father is a hero, and he saved a different world in his younger days!? There’s no way I can believe that this ordinary, middle-aged father of mine is a “Hero.” Diana looks at me, “The Son of the Hero” with a gaze filled with longing. My sister who saw that looks at me with a cold gaze… Before bringing back peace to the other world, the peace of our family is in big trouble! What is going to happen to my peaceful everyday life!?

The MC entered the body of the An family eldest son, An Ziran, an arrogant 16 years old boy who weighed 78 kg (~171-172 lbs), who only knew how to eat, play and sleep. Seeing his current body, An Ziran decided his first priority was to LOSE WEIGHT!

Three days later after he became An Ziran, An Ziran’s father and his biological mother died, which meant as the eldest son he had to take over the family business.

Beside his legitimate first wife, An Ziran’s father also married 3 others women, who all wanted to take over the An family fortune but only the eldest son could be able to touch it, therefore they have to depend on An Ziran in order to live a comfortable live.

An Ziran’s father also had an older brother who is always planning to steal the An family fortune. The elder brother of An Ziran’s father and the woman he married had powerful connections. In order to save the An family fortune, An Ziran has to find a golden thigh to cling on. The butler told An Ziran that there is an engagement between the An family and an influential family. Therefore he takes his sister to that family house to make a connection.

However, during their journey, An Ziran’s younger sister overheard that the son of that family is UGLY, so as a beautiful and spoiled young lady coming from a rich household, she didn’t want to marry him and decided to run away. Without any other choice, An Ziran had to take his sister’s​ place and marry that man, who told him that he would let him go soon, but lied.

- Description from Novelupdates

There are 5 books on the 6 sworn brothers in a serial called streamer (流光系列). ‘They are rich, handsome and powerful. These book are on various types of love as well as on the bond and mateship between the brothers. Book on youngest 6th brother.

Chen Yu Bai (3rd brother) & An Xiao Yi – Chen Yu Bai is a sharp, domineering & cool man whereas An Xiao Yi is a foolish, childish & innocent girl. He is her boss & she is his secretary. He bullies her yet at the same time will not hestitate to protect & shelter her. Thus, she can always rely on him. Their relationship is a funny one on how opposite attracts.

Li Wei Ran (5th brother) & Qin Sang – Li Wei Ran and his cousin Qin Song fell in long with Sang Sang who is An Xiao Yi’s best friend. Sang Sang sees Li Wei Ran as a good man. He is polite, patient and passionate whereas she is independent, intelligent and interesting. They are a perfect pair but she is afraid to love so he has to work hard to convince her he is worthy of her love..

Short sequel on their children.

Reincarnated into a poor youth in an unnamed mountain village in another world, Lu Qing expressed deep helplessness. Fortunately, he awakened an ability to see through the information of objects, giving him a bit of capital for survival. He looked at a patch of grass by the roadside.【Cow Bone Grass, average quality, medicinal, quite effective in treating bone injuries.】He looked at a red carp in the river.【Red Moon Carp, excellent quality, delicious meat, a top-grade tonic.】He glanced at a wild rabbit in the mountains.【Gray Rabbit, common wild rabbit, edible.】…Relying on his innate ability, Lu Qing gradually found his footing in the village, able to survive. Just when he thought he would spend his life peacefully in this ancient world with low productivity, one day, he suddenly saw a figure flying across the sky…