Nowadays, easy-going, relaxing slice-of-life anime are relatively popular: Yuru-Yuri, K-On! and Lucky Star are just some of the many examples that people reference when talking about this niche. In fact, its proliferation has led to there being sub-genres within this sub-genre, with one of the most popular known as iyashikei, or "healing visuals." The goal of this specific sub-genre is to make the audience feel safe and relaxed by showing characters living out calm lives in a beautiful, relaxing environment, like the countryside. But this doesn't mean darker themes are completely absent from such stories, provided you dig a little deeper.
Iyashikei anime began after the 1995 Great Hanshin earthquake and the Tokyo Subway sarin attacks. On top of these tragedies, Japan was experiencing a recession, so the general public needed something that would ease their minds and help them through these troubling times. One series to come out of this time is Yokohama Kaidashi Kikou, or Record of a Yokohama Shopping Trip. The series follows a young protagonist named Alpha Hatsuseno as she runs a little cafe in the Yokohama countryside. She's a cheerful, green-haired android who finds happiness in simple things.
The original manga is 141 chapters long, and received two OVA adaptations, though they only cover 18 chapters. The first OVA came out in 1998, which is the more well-known one, and the other came out in 2002-3. Despite its relaxing environment and the sweet protagonist, there are inklings of something grimmer having taken place.
Humanity is declining in the world of YKK. Alpha's master/sensei has ventured out into the world, leaving Alpha behind to take care of the home. He leaves her a gun to use to protect herself, which is one of the first things we see at the beginning of the manga: Alpha sitting at the table, checking the gun. Something has happened to humanity, and around her, nature is reclaiming the landscape. Throughout the rest of the manga, the water levels are slowly rising and soon begin threatening the cafe. What has happened is never clearly explained but that's not what the series sets out to do. It's to tell a story about the aftermath. Yet hints of a large calamity are still threaded through that story.
As Alpha stays the same, being an immortal android, the children and neighbors she loves grow and change. Some leave to find their own simple life somewhere else. Eventually, she too decides to go traveling for a year in an attempt to grow and learn more about the world and what is left of humanity. She meets more androids like her, all with different personalities and views on "life."
Yokohama Kaidashi Kikou is a bittersweet story that shows the beauty of simplicity among the ruins of civilization. All of the major, world-changing events have already happened. Mankind is slowly going extinct, but those that are alive are living simpler lives than the civilization before. Nature is slowly reclaiming the cities and roadways, and it's only a matter of time before the only living things that will be left are the animals and the androids.
Despite this haunting reality, it's a beautiful end to a chaotic existence. Instead of everyone being wiped out in one huge cataclysmic event or everyone resorting to scavenging and acts of violence to survive, everyone that has survived has found happiness in simplicity.