Two’s company on an unforgettable trip to Japan, writes Kristie Kellahan. It takes about five minutes to convince my sister, Cherie, to join me in Japan . It’s late October when plans for my last-minute work trip to Seoul and Tokyo fall into place.

Three weeks later, business taken care of, my sister and I marinate in the piping hot thermal waters of Beppu’s onsens , feast on chicken yakitori in Osaka and gulp down icy lemon sours, the citrusy cocktails served in izakayas all over Japan. We marvel at the brilliant red, gold and orange autumn foliage as we tour Shinto temples and ride Shinkansen bullet trains from the west to the east of the Land of the Rising Sun. Dodging rambunctious deer in Nara, we see the funny side of Japan and of each other.

Every day, I’m reminded of the Japanese proverb: Good things come to families that laugh. Such is the joy and freedom of international travel with an adult sibling, when there are no kids to consider and Mum is happy at home, healthy and independent. We can avoid the school holiday rush, nabbing affordable flights and hotels at short notice, as we bypass expensive theme parks that hold no interest for us.

This is grown-up fun, with the person I’ve been giggling with for as long as I can remember. Read more: Quieter places to go in Japan if Tokyo feels too busy.