Our group chat is called "See the Ocean at Sixty"

Our group chat for the four of us was created in the autumn of 2016, and we named it with real swagger: "See the Ocean at Sixty."

The night we made it, the four of us had just come from a college roommate's wedding and were sitting at a roadside stall eating skewers. Someone sighed and said, "We'll all marry off to different places. We'll be lucky to see each other once a year." Someone else put down her beer glass. "No. We have to commit to something." Commit to what? Looking at the four of us, all closing on thirty, someone shouted, "At sixty, we go and see the ocean together!" The table howled. Then we actually made the group.

The rules went into the announcement, four of them, written that night while drunk. We have kept them seriously for ten years.

One: meet at least once a year. Whoever misses it pays a red packet.

Two: every year, mail the group a postcard from the city you live in, with the most important thing that happened to you that year written on it.

Three: if anyone's family is in trouble, say so in the group. No being polite.

Four: in the year we turn sixty, wherever we are, four old women go and see the ocean together.

Over ten years the group became the four of us's lifeline.

In 2018 A Zhen's husband's business failed and they sold the flat. She said nothing in the group for six months. The three of us pretended not to notice and simply started taking turns finding reasons to pass by. I brought pork ribs. Xiao Wen brought her son over to play with A Zhen's daughter. Lili was the most direct: she rented a shop unit in A Zhen's compound and opened a children's clothing store, then asked A Zhen to "help out in the shop." Two years later, when A Zhen was back on her feet, she said in the group, "For two years I didn't dare ask anyone for anything, and the three of you kept coming round to bother me." Lili replied, "We agreed no being polite. You were polite. Red packet."

In 2021 Xiao Wen found something and needed surgery. The night before, the three of us kept a video call open and talked until she fell asleep. From under the covers she said, "With you three there, I'm not afraid of the knife." The operation went smoothly. The first thing she said the day she came home was, "When I'm better, at sixty, I go into the water first."

We have sent more than seventy postcards. One says, "Promoted. Dinner on me, whole group." One says, "Divorced, but I've made peace with it." One says, "The baby called me Mama today." One is just a drawing of a bowl of noodles with the caption "Made it myself tonight. Still good." In ten years the four of our lives have gone up and down. Someone lived apart from her husband and then came back together. Someone married a second time. Someone became an executive. Someone became a full-time mother. The lives could not be more different. The handwriting on the postcards could not be more alike. All of it says the same thing: still living, and living well.

Adult friendship does not die of fading. It dies of a broken promise. As long as the promise stands, the friendship is still on its way.

At last year's gathering we read the four rules aloud again and realised something. Seeing the ocean at sixty requires first living to sixty, and living to it in good health. Four middle-aged people who routinely stay up past midnight announced on the spot that they were going in for collective self-preservation.

This is year eleven. Last month Lili sent a photograph. She had been sent on a work trip to an island and had taken a picture at the shore: "Scouting the location. The sea is good. It's just missing you three." Underneath, the three of us replied in unison: "See you at sixty!"

A Zhen, who runs the group, followed with a new announcement. Given everyone's poor attitude to health, the ocean-at-sixty plan now has an added acceptance criterion. All four must be able to carry their own luggage. Whoever ends up in a wheelchair carries the bags.

We all laughed. And then, in the middle of laughing, I felt something settle. Nobody knows how this life will finish. But one thing is certain. In the year we turn sixty, there will be four deck chairs by the water, waiting for four old women, in the same wind off the sea.