That Time I Got Reincarnated as a HENNGE GIP Intern

The view from HENNGE’s 11th floor office, feat. Shobi, Eyad, and me (Cay!)

Hi! My name is Cay, pronounced ケイ (or カイas in isekai if you prefer).

One day I was driving to Walmart through the backwoods of Florida; the next I was hauling two suitcases into the bustling hive of Shibuya, or as it once was called, Bit Valley. The next six weeks would pass in a blur, but they’d be among the best of my life.

I arrived in Tokyo four days before the internship started and met up with the other interns (make sure to check out Shobi’s and Eyad’s stories too!). During that time, I visited Inokashira Park, a place with an inexplicably magical vibe. I later learned it’s also a popular breakup spot for couples, so maybe don’t take your boo. We also watched Superman dubbed in Japanese (I understood nothing except that the dog was terrifying, highly recommend).

Inokashira Park

The Journey Begins

When the first day at HENNGE finally arrived, surreal felt like an understatement. Overwhelmed by the number of names, teams, and floors, but I was ecstatic. I finally met the people I had only talked to over Zoom, enjoyed a Dr. Pepper from the world’s only Dr. Pepper vending machine, and even appeared briefly in the background of a television segment filming HENNGE’s “Welcome Café.”

We were given a bag of essential goodies and got set up right away. Interns don’t have to worry about bringing anything; your phone, laptop, and even umbrella are all provided!

I quickly learned just how open the office is and the collaborative environment it fostered; no assigned desks and a variety of workspaces ranging from completely quiet (the Forest) to more social and dynamic areas (like the Café). Don’t be surprised if you find yourself working beside Ogura-san, the CEO. My favorite spot was the 4F lounge (sometimes the couch).

View from the couch on 4F

Bukatsu

If you’ve read any other articles by previous GIP interns, you’ve probably heard of the bukatsu. They are company clubs centered around any interest you can think of.

Easy-board-game-bu is one such bukatsu that happens every Wednesday night. One game we played really tested our Japanese skills: Gentosha Katakanashi. The idea was to describe a word written in katakana without using any other katakana words. Imagine trying to explain a peanut butter and jelly sandwich without mentioning bread, peanut butter, or jelly; that’s what it felt like. Thankfully, I was allowed to sneak in some English when stuck. At one point, someone got the word repertoire. I can’t even describe that properly in English; truly, chapeau!

Another interesting bukatsu was the diversity-expedition-bu. This club tries new cuisines, and this time, we tried a Czech restaurant: popcorn soup (surprisingly good!), curry, bread dumplings, and more. This somehow sparked a heated (and unresolved) debate on what qualifies as soup, salad, or sandwich.

Karaoke night, popcorn soup, and an Epic musical theater night

Bukatsu for trampoline, rock climbing, Japanese study, sweets, karaoke, musical theater, nihonshu, and many, many more also exist. These are wonderful opportunities for not just trying new things but making genuine connections. You can even start a new bukatsu or restart an inactive one.

Training Montage

The part you’ve (probably) been waiting for: The Training.

Assignment 1 — Full Stack App

In this assignment, we were each tasked with creating a social media web app. Stack: TypeScript, Fastify/Express, React/Vue, DynamoDB, S3, and Caddy (or Nginx if you enjoy pain). Coming from an SQL background, DynamoDB required a whole new way of thinking. With plenty of help from docs, the other interns, and my mentor, I eventually got the hang of it, and learned a ton about architecture, prioritization, and teamwork along the way.

Assignment 2 — DevOps

My first real experience with AWS. This was a cool opportunity to deploy the application we made in assignment one in a production-ready environment. On the first day at HENNGE, Ogura-san told us to “FAIL, FAIL, FAIL — and sometimes succeed”. Well, I did just that! Pro tip: things will break, and that’s okay.

Assignment 3 — [Redacted]

Hint: you get to work on very cool stuff. Shout-out to my mentors for the thorough code reviews, quick debugging skills, and good times.

Over the six weeks, we were also introduced to various teams within HENNGE, where we learned about their work and had the chance to ask questions. It was inspiring to see the passion the teams had and the daily challenges they face.

Mochi, simultaneously the world’s best motivator and distraction

Monthly Technical Session

The Monthly Technical Session (MTS) is a time for developers to get together and present technical topics of interest to each other, and interns get to participate. At first, MTS sounded scary (I’ve taken zero public speaking classes). But by the time it comes around, you’ve already done multiple presentations, so it’s pretty chill.

You get to nerd out on any technical topic you like for about 10–15 minutes, learn about other cool tech and get inspired, and have food and beer afterwards. Seriously, what’s not to like? (Sorry for eating all the Krispy Kreme 🙈)

GIP Lunches (a.k.a. Free Food)

Interns get to have around twelve free lunches, each with two or three different full-timers. It’s a great chance to get to know people in the company, and I got to try stuff I probably never would have otherwise.

Also if you’re vegetarian/pescatarian, no problem. Pre-compiled vegetarian friendly options exist, and at konbini/supermarkets just avoid 肉 (meat), 魚 (fish), and 鰹節 (dried fish flakes).

Also: interns got one free coffee per day. Needless to say, I had many hojicha and matcha lattes.

Side Quests

Weekends and (occasionally) evenings were for exploring Tokyo. Sorry for the dump, but here were some of my favorite adventures:

A Night in Asakusa: I tried the best monjayaki, saw Senso-ji temple, and lost a couple thousand yen in a Taito game center (99% of players quit before they win big and I’m not the 1%).

Day trip to Yokohama: I got a melon soda float from McDonald’s and laid in a park where I saw more Shiba Inus than I ever have in my life. I highly recommend getting one or all of the bike rental apps to get around (you can use your work-provided phone’s Japanese number to sign up!). Later, I tried mayo corn pizza with Shobi before having a near-miss with the last train. A tip: know when the last train runs, or you might be stuck sleeping on the street (and possibly wake up with ten water bottles around you).

View of the Yokohama skyline from Zonohana Park (left) and Yamashita Park (right)

ESCape to Enoshima Island (the Beach Episode): We tried cheese kare pan (mind blowingly good), survived shrimp crackers (never again), and still regret skipping the denim ice cream (Is it Japanese denim? Levi’s? Just blue?).

Kamakura: Big Buddha :) (Did you know you can go inside it?) We also got to see the blood moon rise over the Pacific.

Bridge to Enoshima Island (left) and Kamakura (right)

Catching a Matsuri: I went to Shimokitazawa for the thrifting and stayed for the odori matsuri, or dance festival. These festivals happen around Obon week, so if you’re in Japan during the summer (apply to GIP hehe), it’s the perfect time to experience one! I also recommend going to see hanabi if you get a chance.

Chōfu City Fireworks (left) and Shimokitazawa Bon Odori (right)

Fun Free Museums: The Advertisement Museum, Parasitological Museum (if you dare), Toei Animation Museum, Museum of Package Culture.

Random Food Adventures: Pufferfish (survived), gokiburi sake (yes, that’s cockroach), ice cream sundaes with questionable flavors (basil was the best), and what might be the best vegan ramen in Tokyo (Jikasei MENSHO, though you didn’t hear it from me)

The Hunt for Goshuin: In Japan, you can collect goshuin: stamps from train stations, shrines, and even anime-related spots. My goshuincho (stamp book) is still embarrassingly sparse, but hey, it’s a work in progress.

Advertisement Museum (left), Bunkamura Gallery Exhibition (center), Shibuya Pixel Art Festival (right)

For my stay, I somehow scored a room at a Sakura House in Shibuya with only an eight-minute walk to the office. Needless to say, I loved it and met some amazing people. Share houses are their own kind of adventure; people constantly coming and going from all over the world. What struck me most about living in Tokyo was how effortlessly the city brings together people from so many different cultures. HENNGE was no different. Every day felt like a small exchange of perspectives: over lunch, on the train, or in the share house kitchen.

Shibuya itself is chaos in the best way; you never know who you’ll run into. I actually bumped into one of my favorite musical artists randomly in a Family Mart, so basically I can die happily now. And it never really gets dark. One night I woke up at 2 AM, panicked that it was 2 PM and I had missed work, only to realize my window was just aggressively bright.

Biggest disappointment? Learning that melon pan does not contain melon.

De-incarnation

This internship was one of the best experiences of my life and I am incredibly grateful to have had this opportunity. Thank you to my fellow interns for the laughs, debugging help, and adventures; you guys made this experience truly memorable.

If you’re considering interning at HENNGE, just do it. And if you’re facing a bit of self-doubt, do it anyway. Before I de-reincarnate, I’ll leave you with wisdom from a T-shirt I found at a secondhand shop:

“Make good choices so you don’t have waverer tomorrow.”

Cay, from the US, interned with the HENNGE Global Internship Program from August 1 to September 12, 2025. They are currently a software engineer at HENNGE.