This dataset is a reformatted version of the Japanese portion of wiki40b dataset. When you use this dataset, please cite the original paper:

@inproceedings{guo-etal-2020-wiki,
    title = "{W}iki-40{B}: Multilingual Language Model Dataset",
    author = "Guo, Mandy  and
      Dai, Zihang  and
      Vrande{\v{c}}i{\'c}, Denny  and
      Al-Rfou, Rami",
    booktitle = "Proceedings of the Twelfth Language Resources and Evaluation Conference",
    month = may,
    year = "2020",
    address = "Marseille, France",
    publisher = "European Language Resources Association",
    url = "https://aclanthology.org/2020.lrec-1.297",
    pages = "2440--2452",
    abstract = "We propose a new multilingual language model benchmark that is composed of 40+ languages spanning several scripts and linguistic families. With around 40 billion characters, we hope this new resource will accelerate the research of multilingual modeling. We train monolingual causal language models using a state-of-the-art model (Transformer-XL) establishing baselines for many languages. We also introduce the task of multilingual causal language modeling where we train our model on the combined text of 40+ languages from Wikipedia with different vocabulary sizes and evaluate on the languages individually. We released the cleaned-up text of 40+ Wikipedia language editions, the corresponding trained monolingual language models, and several multilingual language models with different fixed vocabulary sizes.",
    language = "English",
    ISBN = "979-10-95546-34-4",
}