丸山さんは、日本農民美術と自由画教育生みの親、山本鼎氏の有名なアトリエがあった旧神川村大屋に育った。近くに山本鼎氏の親友で、春陽会創設者の一人、洋画家倉田白羊氏がいた影響もあって、十七歳の時から油絵を始め、戦後は自由美術研究所にも一年通った。
間もなく赤松新、中西義男両氏をはじめ、上田の洋画を学ぶ人たちが、東京の岡鹿之助画伯(文化勲章受章者・春陽会)を講師に一週間、洋画講習会を開いた。丸山さんも受講者の一人だったが、やがて回を追うごとに作品の研究会へと変わって行った。丸山さんが岡画伯に師事したのは、その時から。二十六年には、読売新聞の「日本アンデパンダン展」に五十号の『赤いリポンをつけた牛たち』を出展、非凡な画才を認められた。
二年後、春陽会展に五十号の『ストープのある静物』を出展、それ以来、春陽会展に毎年作品を出展、六年前会員に推され審査員になった。この間、赤いカニを描き続け、渡欧。四九年の秋、春陽会から推薦されて八十号の大作『三つの蟹(かに)』を安井曾太郎賞展に出品、好評を得た。この作品は、一本の赤い水平の線で三つのカニを表現した感覚的な絵。師岡画伯から「秀作」と激賞された。(『我が道』掲載誌不詳)
Mr. Maruyama grew up in Ōya, the former Kangawa Village, where the atelier of renowned painter Kanae Yamamoto, the founder of Japanese peasant art and free art education, once stood. Influenced by the presence of Hakuyo Kurata, a close friend of Kanae Yamamoto and one of the founders of the Shunyo-kai art society, he began oil painting at the age of seventeen and, after the war, attended the Jiyū Bijutsu Kenkyūjo (Free Art Institute) for a year.
Before long, prominent figures such as Akamatsu Arata and Yoshio Nakanishi, alongside others studying Western painting in Ueda, organised a week-long Western painting workshop with Shikanosuke Oka, a recipient of the Order of Culture and a member of the Shunyō-kai, as the lecturer. Maruyama was one of the attendees, and over time, these sessions evolved into study groups for discussing works of art. It was from this point that Maruyama began studying under Oka.
In 1951, Maruyama exhibited a size 50 painting titled Cows with Red Ribbons at the Nihon Independant Exhibition, hosted by the Yomiuri Shimbun newspaper, where his extraordinary talent was recognised. Two years later, he exhibited Still Life with Stove (size 50) at the Shunyō art exhibition. From then on, he exhibited works at the Shunyō art exhibition annually, and six years ago, he was elected as a full member, which also made him a judge.
During this time, he continued painting red crabs and made a trip to Europe. In the autumn of 1974, Maruyama was recommended by the Shunyō-kai art society to exhibit his large-scale work Three Crabs (size 80) at the Sotaro Yasui Prize Exhibition, where it received high praise. This piece, characterised by a red horizontal line depicting three crabs, was a sensory-driven painting and was highly acclaimed by Master Shikanosuke Oka, who called it an “outstanding work”. (My Way, published in an unidentified newspaper)