Onsen-Mark (温泉マーク or ♨マーク, Onsen-Mark?) is the homeroom teacher of Tomobiki High School's Class 2-4. His real name is unknown, as even the Principal refers to him as Onsen-sensei (温泉先生, Onsen-sensei?). Onsen Mark could even conceivably be his real name, if he is a nikkei (diaspora Japanese), not implausable given that he is an English teacher. In that case his name with English ordering would be Mark Onsen.

About

Onsen-Mark is Ataru Moroboshi's homeroom teacher and a graduate of Tomobiki High. Throughout the entire run of the series, he is shown teaching various subjects, mainly English, and he is also in charge of student discipline. He formed the Shadow Disciplinary Council, comprised of Shūtarō Mendō and other honor students, which he uses to spy on students who break school rules.

As the series goes on, he becomes more antagonistic towards his students, particularly Ataru and his friends. He is often assaulted by Ataru, Kōsuke Shirai, or Mendō or caught up in explosions and other such unfortunate events that occur in his classroom.

In the manga, he is established as having a wife and child and an elderly mother, but in the anime he is single and lives alone. Because of this, there are many anime scenes where it is implied he is in love with Sakura. In Beautiful Dreamer his dream is shown to be living with a wife who resembles Sakura.

In Beautiful Dreamer, he is the first person to figure out the truth of their situation and is disposed by Mujaki before he can ruin Lum's dream.

He is a very dedicated teacher, despite dealing with students like Ataru. He will often insist on continuing classes even when the school has been damaged or the class is in an unreasonable state. In Boy Meets Girl, he tries to conduct class outside of the school before being thrown into the sky by a sprouting mushroom.

Appearance

He is always seen wearing a suit with the onsen mark (♨) drawn on it. In the manga, the symbol is all over his suit and slacks, but in the anime it is only on his tie and on the back of his jacket.

Personality

He is depicted as a strict teacher while still showing genuine concern for his students.

Trivia

  • While he was Class 2-4's teacher from the start in the manga, various different teachers were used before being introduced in the anime in Episode 36.

Media Appearances

Manga

  • Chapter 4
  • Chapter 14 (15 in wideban)
  • Chapter 16 (19 in wideban)
  • Chapter 22 (23 in wideban)
  • Chapter 24 (24 in wideban)
  • Chapter 30
  • Chapter 36
  • Chapter 38
  • Chapters 75-77
    • Chapter 76
    • Chapter 77
  • Chapter 78
  • Chapter 85
  • Chapter 100
  • Chapter 104
  • Chapter 105
  • Chapter 106
  • Chapter 112
  • Chapter 113
  • Chapter 116
  • Chapter 117
  • Chapter 118
  • Chapter 120
  • Chapter 123
  • Chapters 125-127 (124-126 in wideban)
  • Chapter 128 (127 in wideban)
  • Chapter 131
  • Chapter 133
  • Chapter 135 (138 in wideban)
  • Chapter 141
  • Chapter 149
  • Chapter 152
  • Chapter 154
  • Chapter 158
  • Chapter 159
  • Chapters 160-161
  • Chapter 161
  • Chapter 167
  • Chapter 168
  • Chapter 170
  • Chapter 172
  • Chapter 173
  • Chapter 174
  • Chapter 182
  • Chapters 186-190
  • Chapter 191
  • Chapter 196
  • Chapter 198
  • Chapter 204
  • Chapter 205
  • Chapter 209
  • Chapter 211
  • Chapter 214
  • Chapter 216
  • Chapter 220
  • Chapter 228
  • Chapter 230
  • Chapter 232
  • Chapter 233
  • Chapters 237-239
    • Chapter 237
    • Chapter 239
  • Chapter 240
  • Chapter 241
  • Chapters 242-243
  • Chapter 259
  • Chapter 262
  • Chapter 263
  • Chapter 265
  • Chapter 268
  • Chapters 269-271
    • Chapter 270
    • Chapter 271
  • Chapter 278
  • Chapter 279
  • Chapter 280
  • Chapter 281
  • Chapter 283
  • Chapter 286
  • Chapter 289
  • Chapter 291
  • Chapters 292-293
    • Chapter 292
  • Chapter 298
  • Chapters 301-304 (300-303 in wideban)
    • Chapter 302 (301 in wideban)
  • Chapter 306
  • Chapter 311
  • Chapter 313
  • Chapter 316
  • Chapter 320
  • Chapter 321
  • Chapter 322
  • Chapter 327
  • Chapter 334 (329 in wideban)
  • Chapter 336
  • Chapters 338-340
    • Chapter 338
  • Chapter 351
  • Chapter 353
  • Chapter 354
  • Chapters 356-366
    • Chapter 356
    • Chapter 359
    • Chapter 364

Anime

Gallery

To be added

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