Title: 聖者の行進
Title (romaji): Seija no Koushin
Also known as: When the Saints Go Marching In
Genre: Human drama
Episodes: 11
Broadcast network: TBS
Broadcast period: 1998-Jan-09 to 1998-Mar-27
Theme songs: Ito (1-4, 10-11), Inochi no Betsumei (5-9) by Nakajima Miyuki
Subtitles by: areiacreations (ENG Hard) Byakuya Fansubs (HUN)

Summary
Exploring the perception and treatment of mentally-challenged youth and their similarities to juvenile delinquents in Japanese society, this drama series follows the trials and tribulations of a group of adolescents in a work/study program for mentally-challenged teenagers. Although the program’s intention is to gently “normalize” them for introduction in society, the group is subject to constant physical and mental abuse unbeknownst to their parents and teacher, Ms Hagawa. However, the friendship between Towa, a naive but unusually articulate member of the program, and Arisu, a rebellious schoolgirl, helps both of them learn to overcome their troubles. – (TBS) 

Cast
Ishida Issei (いしだ壱成) as Machida Towa
Sakai Noriko (酒井法子) as Hagawa Momo (music teacher)
Hirosue Ryoko (広末涼子) as Tsuchiya Arisu
Ikariya Chosuke (いかりや長介) as Uno Junichi (lawyer)
Ando Masanobu (安藤政信) as Takahara Ren
Danta Yasunori (段田安則) as Takegami Kosuke (factory boss)
Hinagata Akiko (雛形あきこ) as Mizuma Taeko
Matsumoto Rio (earlier Matsumoto Megumi) (松本莉緒 / 松本恵) as Takahara Rin
Fujita Yumiko (藤田弓子)
Shimizu Shogo (清水章吾)
Mizusawa Aki (水沢アキ) as Takegami Yuko
Saito Yosuke (斉藤洋介) as Manaka Junji (factory chief)
David Ito (デビット伊東) as Takegami Saburo
Yamamoto Michiko
Mitamura Kenji (三田村賢二) as Ayumu’s father
Kato Ai (加藤あい)
Watanabe Kei as Kagami Ayumu
Kobayashi Masahiro (小林正寛) as Inose Tatsuo
Ishibashi Tamotsu (石橋保) as Mukai Tetsuo (math teacher)
Kato Zenpaku (加藤善博)
Oki Naomi
Shiga Matsuko as Arisu’s grandmother
Shinohara Toshiharu
Nakamaru Shinsho (中丸新将)
Kaku Tomohiro (郭智博)
Tsukada Wakano as Ayumu’s mother
Asaka Mayumi (朝加真由美) as Taeko’s mother
Uchiyama Morihiko
Masuko Shizue (増子倭文江) as Ren’s mother
Yamazaki Hajime (山崎一)

Screenwriter: Nojima Shinji (野島伸司)
Music: Senju Akira (千住明)

Other information
The drama is based on a true event referred to as The Mito Incident.
More info at DramaWiki

Amd piano sheets for “Inochi no Betsumei” here.