If you are planning a family trip to Kyushu, you might think of train travel as simply a way to get from Point A to Point B. But in Kyushu, the train ride itself can be the highlight of your vacation. Among the famous “D&S” (Design and Story) trains operated by JR Kyushu, one stands out as the absolute champion for traveling families: the Limited Express “Aso Boy!”
Imagine a train that isn’t just transport, but a moving playground. With a dedicated car filled with toys, a wooden ball pit, and adorable mascot characters covering almost every inch of the interior, the Aso Boy! is designed specifically to make children smile.
In this guide, we will break down everything parents need to know about booking seats, buying the famous bento boxes, and navigating the route between Kumamoto and Beppu. Whether you are following our 7-Day Kyushu Family Itinerary: Fukuoka, Beppu, and Kumamoto by Train or just taking a day trip, this train is a must-do experience.
What is the “Aso Boy!”?
The “Aso Boy!” (derived from “Aso” and “Boy”) is a special limited express train that runs primarily between Kumamoto Station and Beppu Station, traversing the stunning landscapes of the Aso Caldera.
The train’s mascot is “Kuro-chan,” an adorable black dog whose cartoon face appears over 100 times throughout the train—on the walls, the curtains, the seat covers, and even stamped onto the food. For kids, spotting the different poses of Kuro-chan becomes a game the moment you step onto the platform.
Unlike the sleek, business-like Shinkansen, the Aso Boy! is built for leisure. It moves at a relaxed pace, allowing families to soak in the views of active volcanoes and lush greenery. It connects two of Kyushu’s best family destinations: the hot spring paradise of Oita and the historic city of Kumamoto. For a deeper dive into what to do when you arrive at the western end of the line, be sure to read The Ultimate Guide to Kumamoto with Kids: Nature, Volcanoes & History.
Inside the Train: Why Kids Love Car Number 3
While the entire train is charming, parents should focus their attention immediately on Car Number 3. This is the designated “Family Car,” and it is unlike anything you have likely seen on a train before.
The White “Kuro-chan” Seats
Standard train seats can be tricky with a toddler who wants to wiggle or curl up. In Car 3, you will find the unique “White Kuro-chan Seats.” These are special bench-style seats designed specifically for a parent and child to sit together comfortably. The window-side seat is slightly smaller—perfectly sized for a child—so they can look out the window easily, while the parent sits beside them. It creates a cozy “couch” feel rather than a rigid airline-seat vibe.
The Wooden Ball Pit
Yes, there is a ball pit on the train. Located at one end of Car 3 is a pool filled with smooth wooden balls where children can jump in and play. It is often supervised by a train attendant, ensuring safety. For toddlers and preschoolers who usually struggle to sit still for a two-hour journey, this is a lifesaver. It turns “Are we there yet?” into “Can I play longer?”
The Picture Book Library
Next to the play area, there is a small library corner stocked with Japanese children’s books and picture books. Even if you don’t read Japanese, the visual stories are fun for kids to flip through, offering a quiet break from the excitement of the ball pit.
The Panorama Seats: The Best View in the House
If your children are slightly older (perhaps elementary age) and more interested in scenery than ball pits, you might want to book seats in Car 1 or Car 4.
These cars feature “Panorama Seats” at the very front and back of the train. The driver’s cabin is lowered, and the passenger seats are elevated and feature massive curved windows. This gives you a sweeping, unobstructed view of the track ahead. Watching the train wind through the steep switchbacks of the Aso mountains from the front row is a thrilling experience for young rail fans.
If you are generally confused about how seat reservations work in Japan, check out our guide on JR Trains in Fukuoka with Children: Seats, Tickets, and Family Travel Tips for a primer on the basics of ticket rules.
Eating on Board: The Kuro-chan Bento
No Japanese train journey is complete without an “Ekiben” (train station bento), and the Aso Boy! has some of the cutest food options in Kyushu.
The Kids’ Bento
There is usually a specific Kuro-chan Bento available for purchase at the counter in Car 3. The box itself is often shaped like the train or features the mascot, and the contents are kid-friendly favorites like hamburger steak, sausage, and rice. Note that these sell out very fast—often within the first 30 minutes of the journey. If this is a priority, head to the counter as soon as you board.
Sweets and Puddings
If you miss the bento, don’t worry. The onboard cafe sells Kuro-chan printed donuts, creamy custard pudding (a local specialty), and local juices. There are also plenty of souvenirs, from keychains to clear files, which make for great, lightweight mementos of the trip.
The Route: Exploring the Aso Caldera
The journey typically takes about 3 to 3.5 hours between Kumamoto and Beppu. The scenery is spectacular. As the train climbs from Kumamoto into the mountains, you will experience a “switchback” at Tateno Station. The train actually changes direction to zigzag up the steep slope—a rare railway maneuver that the conductor usually announces.
Once you reach the Aso area, you will see the smoking peaks of Mount Aso. It’s a great geography lesson for kids. If you are starting your journey from the east side, you might be coming from a few days of hot springs. If so, our guide to The Ultimate Guide to Oita with Kids: Hot Springs, Sanrio Characters, and Safari Adventures covers everything you need to know about Beppu and the surrounding areas.
Practical Tips for Parents
1. Booking is Essential
The Aso Boy! does not run every day. It generally runs on weekends and holidays, and daily during peak vacation seasons. Furthermore, it is an “All Reserved Seating” train. You cannot just hop on with a general ticket.
- JR Pass Users: If you have a JR Kyushu Rail Pass or a Japan Rail Pass, you can ride this train for free, but you must go to a ticket office (Midori-no-madoguchi) to reserve your seat in advance.
- Booking Online: You can try to book via the JR Kyushu online reservation system before you arrive in Japan, which is highly recommended for the popular “White Kuro-chan Seats” in Car 3.
2. Stroller Strategy
The aisles in the Aso Boy! are decent, but like most Japanese trains, there isn’t a huge amount of luggage space. If you have a large stroller, you may need to fold it and place it in the luggage rack area at the end of the car. If you are traveling light or wondering what to do with your big bags before boarding, consult our guide on Luggage Free & Hands-Free: Temporary Storage Spots in Fukuoka for Families, as similar services (coin lockers) are available at Kumamoto and Beppu stations.
3. One Way is Usually Enough
While the train is fun, 3.5 hours is a long time for a return trip in one day. We recommend incorporating the train into a loop itinerary. For example, travel from Fukuoka with Kids: The Ultimate Travel Guide (Food, Transport, Tips) down to Kumamoto on the Shinkansen, take the Aso Boy! across to Beppu, and then take the Sonic express train back up to Fukuoka. This allows you to see the whole island without backtracking.
4. Grab a Commemorative Stamp
In Car 3, there is usually a stamping station where kids can stamp a piece of paper with a date and a Kuro-chan image. It’s a free and fun activity to mark the memory.
Final Thoughts: Is It Worth It?
Absolutely. For the price of a standard express ticket (or free with your rail pass), the Aso Boy! offers entertainment that keeps children happy for hours. It removes the stress of trying to keep kids quiet in a silent car and replaces it with the joy of exploration.
If you are building your travel plan and need to know how this train fits into the bigger picture, check out our Kyushu Family Itineraries: The Complete Guide to Planning Your 3 to 7-Day Trip. The Aso Boy! is more than just a ride; it’s one of the few times in travel where the journey truly is as fun as the destination.