Through friendship Nathan shows Skye a series of festive family traditions.
They decorate a tree, eat mince pies, throw snowballs, watch an Xmas movie and he even gives her a gift of a Christmas jumper.
But the advert has a bittersweet ending, as Skye has fixed her ship and must return home.
In a tear-jerking moment, . The same one he was wearing the day they met.
John Lewis says it wanted to spread joy, as so many of us couldn't celebrate Christmas in the traditional way last year or share it with loved ones as we would have liked.
It also wanted to remind viewers of the magic of experiencing Christmas for the first time.
The message at the end of the two-minute long advert says: "For a Christmas as magical as your first."
Claire Pointon, director of customer says: "There is nothing more magical than discovering the joy of Christmas for the first time and enjoying your favourite festive moments with loved ones.
"After the last 18 months, we wanted our advert to really celebrate this as we look forward to a brighter future."
The retailer said it wanted to reflect how shoppers were buying Christmas items earlier than usual.
The soundtrack this year is performed by Lola Young, a 20-year-old singer-songwriter from South London.
It is a version of "Together in Electric Dreams", originally released by Philip Oakey, lead singer of Human League, and Italian composer Giorgio Moroder in 1984.
The ad will air on social media from 8am and will be on telly for the first time at 8.15pm during the The Pride of Britain Awards on ITV.
This year John Lewis is selling its biggest range of merchandise, which includes the given to Skye.
It comes in mens, womens and childrens sizes and costs between £14 - £29.
John Lewis Christmas Advert Jumpers -
John Lewis is donating 10% of profits from each jumper to its Give A Little Love charity, which supports FairShare and Home-Start UK.
Its Christmas emporiums, which feature in 11 shops, also help bring the advert to life, with many of the items on sale.
John Lewis has also released two Snapchat lenses to celebrate the launch of the ad.
As well as offering My John Lewis members access to an augmented reality virtual game on its app and website.