Since the number of characters has grown quite a bit, here's a breakdown of those with names. The numbers are from memory, so they might not be exact.
Hisui Umino ♂ (30 years old, 145cm, 50kg)
As the only male character in the story, he's the protagonist.
Short and small, but he's trained a bit, so he's not completely weak. He's strong enough to princess-carry someone like Misago without effort.
Basically a good-natured guy with the soul of a virgin—he can't turn people away or hurt them.
Because of that, he often goes overboard with his "service."
He's very proactive about sexual stuff—he'll go all the way if given the chance. He doesn't mind being the one initiating or the one being initiated.
There just weren't any situations like that on the other side.
He can ejaculate three times a day, which is strong by Earth standards, but not super rare.
But here, that makes him practically a monster.
What's more, since coming here, he's been secretly eating stamina-boosting meals made by Aoba, so he's producing way beyond what he claims.
Misago Umino ♀ (20 years old, 170cm, 60kg)
Bird image: The osprey. The type that hangs around water and snatches koi or bass.
She's the first heroine. Trains on the beach, slightly tanned, and a stamina monster.
Likes looking for jade at Jade Coast, though that knowledge is common sense around here.
At first, she just wanted to lose her virginity—didn't care with whom—but after sleeping with Hisui, she fell head over heels.
Yata Umino ♀ (Age undisclosed)
Visually a "loli grandma." The oldest character who looks deceivingly young.
Bird image: Yatagarasu—the mythical three-legged crow, a divine beast or godly creature.
Usually wears a yukata or traditional clothes. A respected figure or leader in the land.
Though deceased, she was the "main wife" of Kohaku's harem, with many stepdaughters and sisters-in-arms in high positions. She's got massive influence and is considered by some to be like a youkai.
Her wealth comes entirely from dividends, and if we assume a 1% dividend, she's got around 10 billion USD in financial assets. A real monster financially.
She's lived long enough to read people like a book and seems to predict the future with how ahead of the game she is.
She's into sexual things, but claims her periods have stopped, so she prefers "using her mouth" to avoid wasting anything. She even thinks it tastes pretty good.
Tsugumi Umino ♀ (37 years old, 160cm, 55kg)
Bird image: Thrush. Misago's mother and, emotionally, everyone's mom.
A bit unlucky and has had a tough life. Looks young, with a calm older-sister vibe.
Became well-known in some circles for kicking out a man sent after Kohaku's death. Generally well-regarded. Some men resent her, but it's no big deal.
Suzume Tagami ♀ (22 years old, 140cm, 45kg)
Bird image: Sparrow.
Think of a sparrow inn or Benienma-type.
Injured her eye in childhood when cigarette ash from "that man" got into it. Unfortunately remembers everything vividly—one of those with strong memory—so she's still afraid of men.
Her slightly poor eyesight lets her use digital contact lenses to manage info, and she's a master manipulator and manager of people.
She's told that Hisui doesn't scare her, but because she's afraid of the "male" trait itself, she's in mental rehab in various ways.
Hachikuma Yamano ♀ (24 years old, 190cm, 80kg)
Bird image: Oriental Honey-buzzard—a hawk that raids beehives, hence the name. A migratory bird.
Not related, but she loves sweets like honey. Raised by gourmet chef Aoba, and even eats bee larvae.
She used to be constantly hungry as a kid, so she eats everything and finishes her plate.
Professionally a bodyguard. High combat ranking. Tallest among the main heroines.
Has a very pretty face, but her muscles and height make her intimidating to those who aren't used to it.
She's insecure about her height, but Hisui said he liked it, so she adores him for it.
Kiyora Minazawa ♀ (23 years old, 150cm, 45kg)
Male protection officer.
Petite and small, but compensates with a loud voice. Tends to step back while barking like a Chihuahua—she instinctively keeps her distance and reacts late on purpose.
Fairly capable in combat, and very sports/martial-arts-oriented.
Never had a normal interaction with a decent man, so Hisui's hug was a massive shock to her.
Though people like her are common in this world, she was an orphan dropped off at a baby hatch, and longs deeply for a happy family with loving parents.
Sometimes talks about imaginary pregnancies, though she knows they're impossible. It's just a wishful fantasy.
She also doesn't have much experience with herself, so she's very innocent