IrisCTF2025 - OSINT - Not Eelaborate

Challenge description

After my long train ride, I visited a deer park and got to feed the wildlife. There were so many restaurants to choose from but I was craving eel. I really like the soup mixed in with the rice and fish. The wasabi threw me off since I don’t normally have it served this way. I would recommend this place if you want to find a quiet restaurant to eat at, and wouldn’t mind finding a few small fish bones. Eels are known to carry lots of tiny bones it’s inevitable that you’ll find it in a lot of places.

Question: What is the full name of the restaurant?

By: Lychi

Flag : irisctf{Edogawa_Kintetsu_Nara}

Ressources

As with the previous OSINT challenges, we were given access to Adam Holmes’ food blog, containing several articles, photos, and reviews of the restaurants he has visited. The website could be accessed via this URL.

The challenge description pointed to one of the reviews Adam shared on his blog. In addition, we were provided with the following image:

Tools

As this is an OSINT challenge we won’t need any tool to solve it. We will only need a web browse, I well be using Google Chrome.

Since this is an OSINT challenge, we didn’t require any specialized tools. A simple web browser sufficed for our needs, I opted to use Google Chrome.

Resolution

Initial Analysis

Exploring Adam’s blog, we noticed he had shared a few articles one or two days prior, where he mentioned visiting a friend in Japan. This clue strongly suggested that the picture was taken somewhere in Japan.

Additionally, in the review, Adam mentioned a deer park. From this detail, we hypothesized that the restaurant in question might be located near a deer park in Japan. The fact that the restaurant served eel, as shown in the picture of the dish, further narrowed down our search criteria.

Identifying the deer park

Our first step was to investigate well-known deer parks in Japan. The most famous, and the first to appear in our search, was Nara Park. Given that Adam is a tourist and Nara Park is one of the most popular tourist destinations in Japan, it seemed highly likely that he visited this park.

Identifying the dish

Now that we have a lead on the area where Adam likely had his eel dish, we need to identify its exact name. This step was quite straightforward: a quick search for Japanese dish with eel revealed that the dish in question was Unagi (grilled freshwater eel).

We could have deduced this information even faster by checking the image filename, which was Unagi_Bowl.png.

Pinpointing the restaurant

With a strong assumption that the location was near Nara Park and that Adam had Unagi, the next logical step was to identify a restaurant serving this dish in the area.

To do this, we used Google Maps:

1. Search for Nara Park to center the search area.
2. Search for Unagi within the region to list restaurants that serve eel dishes.

From this point, the process was simple: I manually browsed through the restaurant listings, checking their images to find one that matched the dish in Adam’s blog post. Fortunately, I didn’t have to search for long as one of the first results looked very promising.

Comparing it with Adam’s picture, the similarities were striking!

Conclusion

After verifying all the details, I identified the restaurant where Adam had his Unagi: Edogawa Kintetsu Nara.

Interestingly, this restaurant also goes by another name: Unagi no Nedoko Edogawa. However, to validate the challenge, we had to use the name displayed on Google Maps.

Thank you for reading my write-up! I hope it was clear and helpful. See you in the next challenge!

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