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Long, long ago,
there lived a girl named Kohaku, a daughter of the King of Heaven.
She had an older sister named Ruri that she loved dearly. Her sister was sick and needed the healing water of the River of Heaven to be brought to her daily to keep her healthy. The only one fast enough and strong enough to bring that water was Kohaku, and she did it without complaint, bringing water to Ruri every day for years.
There lived a boy named Senku on the other side of the River of Heaven. He was a scholar of both the heavens and the earth below, studying the rules of nature and man alike.
He observed Kohaku on her daily journeys (for she took several a day), wondering what such a strong and healthy woman could need so much healing water for.
“Where are you going?” he called to her one day.
She ignored him and went on her way.
“Why do you need the water?” he called to her the next day.
She ignored him and went on her way.
For a week, Senku asked questions that Kohaku would ignore. Finally, curious and a bit frustrated, Senku decided he would build a bridge and ask her directly.
Kohaku was curious about this man as well—but she would not stop to talk while her sister needed water. When she came to the river one day to see a bridge crossing the river and the man standing on her side of it, she was startled but did not stop.
“Who are you?” the man asked, leaning against his bridge. “Tell me your name, unless you’d rather have me call you ‘lioness.’”
“Tell me yours first,” she said, putting her jug into the river to fill.
“I am Senku.”
“I am Kohaku.” And then she ran off, her jug full of water.
The next day, he asked, “Why do you need this water? You’re obviously healthy.”
“It’s for my sister. She’s very sick.”
The next day, he asked, “Do you do anything besides bring water to your sister?”
“No,” she said as she jogged away.
The next day, he asked, “Why do you need to take so many trips?”
“I can only carry so much at once, and my sister needs a lot of water.”
He was gone the next few days, and even though his questions were kind of annoying, Kohaku found that she missed him. She didn’t get to talk to many people. But she figured he had gotten bored—she did, after all, do the same thing every day.
And then he was back, with a weird thing behind him.
“It’s a cart,” he told her. “It can hold more than one jug of water. You pull it behind you.”
And suddenly Kohaku had at least half a day to herself, something she couldn’t even remember having before.
Intrigued by Senku’s invention, and very grateful, she went back to the river.
“Thank you,” she said. “What do you want in return?”
He shrugged. “I don’t need anything. I just wanted to help.”
Kohaku thought for a moment. “Well, could you use my help with something? I’m very strong and very fast, and you don’t look strong or fast at all.”
Senku cackled at her words. “So rude, lioness! But you’re right, I’m not strong or fast, so if you’d like to help me, I’d appreciate it.”
So she helped him with the tasks he struggled with, like cutting up wood, reaching high places, or finding rare minerals hidden in the earth. He told her about all the things he’d learned as they worked together, about math and architecture and physics and so much more that she didn’t understand. She helped him as he observed the humans below the heavens, her keen eyesight able to pick out things he was curious about. Even when she had more than paid him back for the cart, she kept coming back, to learn and to help.
And though he never said so directly, Senku greatly appreciated Kohaku’s help. If he ever thought of something that he thought she might like, he’d make it for her. If he saw something she might like, he’d show it to her.
Once they had known each other for a while, Senku asked, “Why doesn’t your sister move closer to the river?”
“She has to stay in the Palace of Heaven. It keeps her alive.”
“And the water keeps her healthy?”
“Yes.”
He hummed thoughtfully and focused on the fabric he was stitching together. “Why are you the only one getting the water?”
Kohaku did not answer this question at first, and Senku could see that it had pained her to think about it, so he did not repeat it.
“My sister,” she said at length, “can do her duties whether or not she is healthy. She doesn’t complain, so no one knows how much pain she’s in when her illness is very bad. I know her, though. I know she’s always trying to hide her pain, and I know that the water from the River of Heaven helps her. So I bring her water every day without fail.”
Senku thought about what he would do in Kohaku’s position, and was glad that Ruri didn’t have to depend on a weakling like him—she had a lioness for a sister, who would do whatever it took to help Ruri feel better.
Neither of them knew how many days or months or years they spent together like that, creating and talking and observing, but Kohaku began to notice that Senku spent a lot more time looking at earth, muttering about inventions they could use, as time went on.
So she was not surprised when he told her that he wanted to leave the heavens to journey down to dwell among the humans, to help them—for they badly needed it.
He did not ask her to come with him, and she did not ask if she could. She was a dedicated sister and would not leave her sister to suffer in her absence.
But he did hold out his hands, palms up, eyes more gentle than she can remember seeing them. She put her hands in his and he gently passed his calloused thumbs over her knuckles. “I’ll miss your strength, lioness,” he said, the closest he would come to saying he would miss her.
She squeezed his hands. “Well, I won’t miss your annoying questions at all,” she teased, her heart full of emotion.
Senku swallowed, then said, “Every year, every year on this day, I will build a bridge to visit here, just for a night.”
“Then every year I will be here to meet you,” she promised. And then she had to leave, had to run back to the palace, afraid of being tempted to leave her sister behind.
The first year, she did not watch the earth below at all, instead trying to spend time with her sister. When the anniversary of Senku’s departure arrived, she delivered the water, then went to the place Senku’s bridge would connect the heavens and the earth. She watched him try to build it, but the materials on earth were inferior to the ones in Heaven, and the bridge was not completed in time.
In fact, it was not completed at all. Senku worked night after night on the bridge (his days being dedicated to helping humans), having expected it to go as smoothly as the one he built to journey to the earth. He worked on it until the next anniversary of his departure, and the next, and the next, and on and on and still it was nowhere close to being done. After years of work and failure, he now knew it was impossible to build a bridge back to Heaven with the materials of earth.
With a heavy heart, he abandoned the project on the day of the anniversary (for he had not and would not forget). He looked up to the heavens, even though he could no longer see the land of Heaven, and hoped Kohaku didn’t think he had forgotten her or didn’t care. Did she still remember him? Did she still want to see him again?
“I’m sorry,” he whispered, turning to leave, feeling sick with regret.
And a shining star fell to his feet.
Confused, he picked it up and examined it. The light was still bright within it—it hadn’t burned out and fallen.
And then another star fell, and another, star after star littering the ground around him.
He smiled, for who did he know that was strong enough to throw the stars from the sky?
Stars in hand, he started a new bridge, this one built of a material as heavenly as it got—the stars themselves.
And he built his way up to Heaven and saw Kohaku again. She was panting from exertion after throwing him the stars he needed, but smiling brightly. “I should have known,” she said, “that you needed my help. I’m sorry I didn't think of it sooner.”
They spent the rest of the night together, talking as they did before, enjoying their time together. And they had missed each other so greatly, so dearly, that neither of them thought it was strange that they sat side-by-side, arms wrapped around each other.
Senku left Heaven just before the sun rose and the stars vanished, with the promise that he’d see her in a year if she would help him again.
He kept that promise, and Kohaku would throw stars down to help him. The only time the bridge wasn’t built was when it rained and the stars didn’t come out, and Kohaku and Senku would both deny shedding any tears when that happened.
It was actually a human that Senku had grown fond of, a young inventor named Chrome, who thought of something that might help Kohaku the most. Farming had recently been invented by humans, and Chrome had noticed that some areas didn’t get enough water to support crops. He built a series of channels and bridges to carry the water from the river to where it was needed, and Senku realized he could try something similar in Heaven.
He blessed Chrome for his ingenuity and waited impatiently for the night when Kohaku would throw stars to the earth.
Building the water-carrying system was ridiculously easy in Heaven. Senku asked Kohaku to build a pond where Ruri could reach it while he worked on something else. Kohaku was confused, but she trusted Senku and got to work. Soon Ruri had a constant fresh supply of water from the River of Heaven to use at her convenience, and Kohaku no longer needed to carry heavy jugs back and forth.
Before Kohaku could ask, Ruri gave her blessing for her sister to journey to earth with Senku. “I know you’ve missed him greatly,” said Ruri as she hugged her sister goodbye. “You shine brighter when you’ve been together. Thank you for taking care of me for so long.”
And Senku and Kohaku left Heaven to live on earth together, to build a life together, working side by side to help people as they built and invented and worked through problems that seemed impossible when faced alone.
And they were very happy.