This download is totally safe. Narutan is the developer of マッチ棒パズル・数式編 which can be found in the Puzzle Games category. The game was downloaded and set up by over 10K users and its most recent stable release was on Jun 2, 2017.
Google Play shows that this application is rated 2.4 by its users. You can get the installation package of マッチ棒パズル・数式編 1.1 for free and have a look at users' reviews on Droid Informer. The app works fine on Android 4.0 and higher.