This paper presents Mrs kanji, a web application for learning Japanese kanji characters developed by authors over the past one and a half years. This study aims to create and develop applications that are used for learning and memorizing kanji letters based on the website application, which contains 101 letters that have been grouped in a thematic form accompanied by illustrative picture learning models, mnemonic hints in English and Japanese, how to read meaning (Indonesian and English), examples of words, search features (hiragana, romaji, kanji, and meaning), glossary and exercises and three types of practice or quiz. The method used in this study is DBR (Design-Based Research) with a descriptive contextual model. The product outcome is problem-based learning so that the survey was first carried out with a non-test instrument in the form of a questionnaire taken randomly or random sampling twice with the first survey results participated by 52 respondents consisting of beginners and people who were proficient in Japanese with the aim to identifying the needs of users regarding the applications. The second survey was administered to 19 people consisting of users and experts who tested and evaluated the website-based applications. The results of the data analysis show that the application has fulfilled the aspects of effectiveness, validity, and practicality with the category of "Good". The available kanji is incomplete so it is recommended that further research can develop this application better.