Japanese is written in a mixture of Kanji, Katakana, and Hiragana.
It can be written: 日本の文化
It is most often written as: フランス
If "Mery" is a proper name, non-Japanese names are written in Japanese using the phonetic script, which can only approximate English sounds, since many English language sounds do not exist in Japanese. The word "Mery' doesn't exist in the English language. Maybe checking for spelling mistakes in your question would help. The English word "Merry" is "陽気な" when written in Japanese script, or "Yōkina" when in European script. The English word "Mercy" is "慈悲" when written in Japanese script, or "Jihi" when in European script.
It can be written: ジェレミー
It may be written using Kanji (traditional pictograms), Katakana (simplified pictograms), or Hiragana (syllable script).
In Japanese, London is written as ロンドン and pronounced as "Rondon." The katakana script is used for foreign place names, and this adaptation captures the pronunciation of "London" in Japanese phonetics.
The verb "to walk" is 'aruku' in Japanese, written: 歩く If you're referring to "walks" in the sense of "I like taking walks" or "strolls," then you may say 'sanpo,' written: 散歩
水
Japanese is written in five scripts: kanji, hiragana, katakana, romanji, and furigana. Each script serves a different purpose in the written language.
犬
ボリューム
Japanese is written with a combination of five scripts: Kanji (characters borrowed from Chinese), Hiragana, Katakana, Romaji (Latin script), and Arabic numerals.