chasen software package provides 2.4.5-12, you can install in your Debian 8 (Jessie) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install chasen
chasen is installed in your system.
Make ensure the chasen package were installed using the commands given below,
$ sudo dpkg-query -l | grep chasen *
You will get with chasen package name, version, architecture and description in a table
| Distro | Debian 8 jessie |
| Section | Miscellaneous |
| Package | chasen |
| Version | 2.4.5-12 |
| Description | 2.4.5-12 |
| Sub Section | Misc |