Here's a really great implementation of Web GIS for Crime Information Maps for Tokyo Metropolitan City by Esri Japan. It is a portal that shows several crime themed maps meant to encourage crime prevention.
Some general information and background can be found on this website in english,
Office for Youth Affairs and Public Safety
The ArcGIS Online landing page is here: https://bouhan-tokyo.maps.arcgis.com/home/index.html
It is in Japanese, but you can open in Chrome and translate the page contents to check it out for yourself.


List of beautiful interactive maps from left to right in the featured gallery:
1 "子供の安全マップ" - Child Safety Map
https://bouhan-tokyo.maps.arcgis.com/apps/webappviewer/index.html?id=f41347b901034bdf808ebce14ee1896...
2 "特殊詐欺情報マップ" - Special Fraud Information Map
https://bouhan-tokyo.maps.arcgis.com/apps/MapSeries/index.html?appid=125ebee28d624b109304b49b9b17638a
3 "町丁字別犯罪情報マップ" - Crime Information Map by Town District
https://bouhan-tokyo.maps.arcgis.com/apps/MapSeries/index.html?appid=2945e6613afa469baef87f60aea5208...
4 "防犯団体活動情報マップ" - Crime Patrol Community Volunteer Map
https://bouhan-tokyo.maps.arcgis.com/apps/MapSeries/index.html?appid=5bbcbfa303b9466da272558cd273b80...
5 "施策情報マップ" - Crime Prevention Measures and Policies Map
https://bouhan-tokyo.maps.arcgis.com/apps/MapSeries/index.html?appid=6967a8b9076a4548b31f20fb17956c2...
6 "放置自転車情報マップ" - Abandoned Bicycle Information Map
https://bouhan-tokyo.maps.arcgis.com/apps/webappviewer/index.html?id=f3c6d36aa16e42a686a26a620f001f6...
Many of the web apps were built using Web AppBuilder for ArcGIS, and in some instances also nested in a Map Series template.
Special thanks to chiyo kigasawa; Masanobu HIRANO; and Brett Dixon for sharing this great site!
Enjoy,