
For pretty much every parent, there will eventually come that awkward day when their child asks questions about where babies come from. Parents have to tread a fine line with the information that impart, at once wanting to preserve their curious progeny’s innocence but also not wanting to send them out into the wild with tales of storks and cabbage patches.
Thanks to Ryo Shirakawa, now there’s a fun way to teach kids about sexual reproduction without actually having to deal with it: Sperm Vs Egg (Seishi Vs Ranshi; localized to Seed and Egg in English) for smartphones.
Envision this scenario if you will. A young girl walks into the kitchen while her father skims the financial section of the newspaper and sips on a cup of coffee. She asks about her new baby brother, saying, “Daddy, how did Tommy get inside mommy’s tummy?”
Momentarily caught off guard by this question loaded with sexually explicit information, the father panics. Then he remembers that he has the hit game Sperm Vs Egg on his iPhone and boots that puppy up! “It’s er… ah… Oh, here! This will show you.” Now that’s some clutch parenting.
Sperm Vs Egg accurately simulates the conditions inside the human uterus – dark and full of viruses. The player must navigate an ovum through the virus minefield to collect as many spermatozoons as possible.
However, so as not to bore the child with too much dull science the game has a back story, as outlined on the App Store page:
It is the year 2999 and humans are close to extinction. Despite their best efforts, mankind has been unable to produce children for many years. Many theories have been tested, but none have been successful. Hope grows dim. Slowly but surely the women have grown older, eventually reaching menopause, unable to give birth. When suddenly, a special egg was found, able to fertilize more than once. This is our chance!!! She needs your help! Fertilize as many good eggs as you can while avoiding the bad viruses. With your help we can populate the earth!
With a dramatic backdrop and authentic biology intermingled, there’s no way a curious tyke won’t walk away informed and well-adjusted while you can get back to keeping an eye on the Goldman Sachs Commodities Index.
The games itself is actually quite well made. The ovum handles like a dream, with the player directing it around the screen using the virtual control pad that is comfortably laid out on the screen. The challenge level is, however, high, leading to games that last a mere ten seconds later on, which rather fittingly is about as long as it takes for real conception.
Online reviews have thus far been positive, calling Sperm Vs Egg “Addictive” and one that people want to “play over and over.” So, whether you have a youngster or just want a fun game to kill a few minutes, stop on by the App Store for the free download. Just remember to turn the volume down when playing in public. The moaning woman sound effect might make people think you’re up to something less wholesome.
Source: App Store via IT Media (Japanese)
▼ My high score was 99 babies in a single egg. Seven higher than I got in real life.



Studio Ghibli store Donguri Republic announces opening of first-ever store in America
Japanese ninja certification exam attracts 131 candidates from Japan and abroad
Japanese sweets shop sells an ohagi so exquisite it sells out by noon
7-Eleven Japan to start selling Vietnamese banh mi sandwiches this summer
Starbucks Japan releases new Frappuccino, tea and soda drinks for summer
Studio Ghibli store Donguri Republic announces opening of first-ever store in America
Japanese ninja certification exam attracts 131 candidates from Japan and abroad
Japanese sweets shop sells an ohagi so exquisite it sells out by noon
7-Eleven Japan to start selling Vietnamese banh mi sandwiches this summer
Starbucks Japan releases new Frappuccino, tea and soda drinks for summer
Forget Tokyo go-karts – there’s a new way to sightsee on four wheels in Japan
Suspected Japanese ice cream cartel under investigation for price-fixing
Studio Ghibli adds new My Neighbour Totoro music box to its anime merchandise store in Japan
All-you-can-eat cheese restaurant in Tokyo is a hidden gem not many people know about
Pokémon coming to Japan’s highway rest stops with exclusive merch and stamp rally this summer
New Japanese overnight train coming to connect Tokyo with Tohoku in sleep-travel style
Universal Studios Japan is giving Frieren anime fans the chance to make unforgettable memories.
Tokyo’s life-size Gundam is getting a new look before its end-of-summer removal
Japanese bento shop touches hearts by selling super cheap boxed lunches for around a dollar
7-Eleven Japan joins the craze for Korean Gamja Cheese Balls
Starbucks Japan releases new limited-edition summer drinks…and a pastry for dunking
Lawson upsizes convenience store food for a limited time with two must-try Japanese meals
Uniqlo reveals third round of massive 100-year-anniversary manga T-shirts for Jump’s Shueisha
Even at twice regular Daiso price, this handy item is still great for summer travel in Japan
New official Ghibli anime food cookbook will teach you how to make Ponyo’s ramen and more
Japanese convenience store Lawson launches new “mini supermarket” chain, L Minimart
Japan’s real-world Pokémon hot spring’s first photos are here![Photos]
Kyoto public junior high school becomes first in Japan with a hoodie school uniform
Japan’s human washing machines will go on sale to general public, demos to be held in Tokyo
Starbucks Japan releases new drinkware and goods for Valentine’s Day
We deeply regret going into this tunnel on our walk in the mountains of Japan
Starbucks Japan releases new sakura goods and drinkware for cherry blossom season 2026
Japan’s newest Shinkansen has no seats…or passengers [Video]
Put sesame oil in your coffee? Japanese maker says it’s the best way to start your day【Taste test】
Japan reportedly adding Japanese language skill requirement to most common foreigner work visa
Japan’s 5.3 million beautiful Hitachi Nemophila flowers are now in full bloom[Photos]
Pokémon and Ikea Japan cross over into each other’s worlds with collaboration events
Wisteria season starts early with blooming of Japan’s Great Wisteria in its beautiful garden
Forget Tokyo go-karts – there’s a new way to sightsee on four wheels in Japan
Suspected Japanese ice cream cartel under investigation for price-fixing
Studio Ghibli adds new My Neighbour Totoro music box to its anime merchandise store in Japan
All-you-can-eat cheese restaurant in Tokyo is a hidden gem not many people know about
Pokémon coming to Japan’s highway rest stops with exclusive merch and stamp rally this summer
Studio Ghibli releases new anime character fans to keep fans looking and feeling cool this summer
New adorable Osaka foodie destination, Chiikawa Bakery Osaka, opening soon with crazy ramen bread
Starbucks Japan releases new limited-edition summer drinks…and a pastry for dunking
Japan’s Pokémon Slowpoke Train goes on hiatus, but a mini version could be yours to own
Lawson upsizes convenience store food for a limited time with two must-try Japanese meals
Tokyo has a cafe that prohibits talking inside, and here’s why it’s awesome
Gama Land, the weird Japanese amusement park celebrating toads, is now like a ghost town
Studio Ghibli adds My Neighbour Totoro futon bedding to its anime store in Japan
Lawson Japan releases a crazy new product to remind us it’s not just famous for convenience store food